User's Guide

Oracle® Database Gateway for SQL

Server

User's Guide

21c

F31875-02

January 2021

Oracle Database Gateway for SQL Server User's Guide, 21c

F31875-02

Primary Author: Rhonda Day

Contributing Authors: Vira Goorah, Juan Pablo Ahues-Vasquez, Peter Castro, Charles Benet, Peter Wong,

Govind Lakkoju

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Contents

Preface

Audience x

Documentation Accessibility x

See Also:

Oracle Database Heterogeneous Connectivity User's Guide for more

information about Heterogeneous Services.

1.3 About Oracle Database Gateway for SQL Server

The capabilities, SQL mappings, data type conversions, and interface to the remote

non-Oracle system are contained in the gateway.

The gateway interacts with Heterogeneous Services to provide the transparent

connectivity between Oracle and non-Oracle systems.

The gateway can be installed on any machine independent of the Oracle or non-

Oracle database. It can be the same machine as the Oracle database or on the same

machine as the SQL Server database or on a third machine as a standalone.

Chapter 1

About Heterogeneous Services Technology

1-2

SQL Server Gateway Features and

Restriction

After the gateway is installed and configured, you can use the gateway to access

SQL Server data, pass SQL Server commands from applications to the SQL Server

database, perform distributed queries, and copy data.

• Remote Insert Rowsource

A remote insert rowsource feature allows remote insert requiring local Oracle

data to work through the Oracle database and Oracle Database Gateway. This

functionality requires that the Oracle database and the Oracle Database Gateway

to be version 12.2 or later.

• Using the Pass-Through Feature

The gateway can pass SQL Server commands or statements from the application

to the SQL Server database using the

DBMS_HS_PASSTHROUGH

package.

• Executing Stored Procedures and Functions

Using the procedural feature, the gateway can execute stored procedures that are

defined in the SQL Server database.

• CHAR Semantics

This feature allows the gateway to optionally run in

CHAR

Semantics mode.

• Multi-byte Character Sets Ratio Suppression

This feature optionally suppresses the ratio expansion from SQL Server database

to Oracle database involving multi-byte character set.

• IPv6 Support

Besides full IPv6 support between Oracle databases and the gateway, IPv6 is also

supported between this gateway and SQL Server database.

• Gateway Session IDLE Timeout

You can optionally choose to terminate long idle gateway sessions automatically

with the gateway parameter

HS_IDLE_TIMEOUT

• Remote User-defined Function Support

User-defined functions in a remote non-Oracle database can be used in SQL

statements.

• Database Compatibility Issues for SQL Server

SQL Server and Oracle databases function differently in some areas, causing

compatibility problems.

• Known Restrictions

These topics describe known restrictions in Oracle Database Gateway for SQL

Server and includes suggestions for dealing with them when possible.

• Known Problems

These topics describe known problems with Oracle Database Gateway for SQL

Server and includes suggestions for correcting them when possible.

2-1

2.1 Remote Insert Rowsource

A remote insert rowsource feature allows remote insert requiring local Oracle data to

work through the Oracle database and Oracle Database Gateway. This functionality

requires that the Oracle database and the Oracle Database Gateway to be version

12.2 or later.

By Oracle Database design, some distributed statement must be executed at the

database link site. But in certain circumstances, there is data needed to execute

these queries that must be fetched from the originating Oracle Database. Under

homogeneous connections, the remote Oracle database would call back the source

Oracle database for such data. But in heterogeneous connections, this is not viable,

because this means that the Foreign Data Store would have to query call back

functions, or data, that can only be provided by the Oracle instance that issued the

query. In general, these kinds of statements are not something that can be supported

through the Oracle Database Gateway.

The following categories of SQL statements results in a callback:

• Any DML with a sub-select, which refers to a table in Oracle database.

• Any

DELETE

INSERT

UPDATE

or "

SELECT... FOR UPDATE..."

SQL statement

containing SQL functions or statements that needs to be executed at the

originating Oracle database.

These SQL functions include

USER

USERENV

, and

SYSDATE

; and involve the

selection of data from the originating Oracle database.

• Any SQL statement that involves a table in Oracle database, and a

LONG

LOB

column in a remote table.

An example of a remote

INSERT

statement that can work through the remote insert

rowsource feature is as follows:

INSERT INTO gateway_table@gateway_link select * from local_table;

2.2 Using the Pass-Through Feature

The gateway can pass SQL Server commands or statements from the application to

the SQL Server database using the

DBMS_HS_PASSTHROUGH

package.

Use the

DBMS_HS_PASSTHROUGH

package in a PL/SQL block to specify the statement to

be passed to the SQL Server database, as follows:

DECLARE

num_rows INTEGER;

BEGIN

num_rows := DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE@MSQL('command');

END;

Where command cannot be one of the following:

•

BEGIN

TRANSACTION

•

COMMIT

•

ROLLBACK

Chapter 2

Remote Insert Rowsource

2-2

•

SAVE

•

SHUTDOWN

•

RELEASE

•

SAVEPOINT

•

CONNECT

• SQL Server tool commands

The

DBMS_HS_PASSTHROUGH

package supports passing bind values and executing

SELECT statements.

Note:

TRUNCATE cannot be used in a pass-through statement.

See Also:

Oracle Database PL/SQL Packages and Types Reference and Chapter

3, Features of Oracle Database Gateways, of Oracle Database

Heterogeneous Connectivity User's Guide for more information about the

DBMS_HS_PASSTHROUGH

package.

2.3 Executing Stored Procedures and Functions

Using the procedural feature, the gateway can execute stored procedures that are

defined in the SQL Server database.

It is not necessary to relink the gateway or define the procedure to the gateway, but

the procedure's access privileges must permit access by the user that the gateway is

logging in as.

Standard PL/SQL statements are used to execute a stored procedure.

The gateway supports stored procedures in three mutually exclusive modes:

• Normal mode: Have access to

OUT

arguments only

• Return value mode: Have a return value for all stored procedures

• Resultset mode: Out values are available as last result set

2.4 CHAR Semantics

This feature allows the gateway to optionally run in

CHAR

Semantics mode.

Rather than always describing SQL Server

CHAR

columns as

CHAR(n BYTE)

this feature describes them as

CHAR(n CHAR)

and

VARCHAR(n CHAR)

. The

concept is similar to Oracle database

CHAR

Semantics. You need to specify

HS_NLS_LENGTH_SEMANTICS=CHAR

gateway parameter to activate this option. Refer to

Initialization Parameters for more detail.

Chapter 2

Executing Stored Procedures and Functions

2-3

2.5 Multi-byte Character Sets Ratio Suppression

This feature optionally suppresses the ratio expansion from SQL Server database to

Oracle database involving multi-byte character set.

By default, Oracle gateways assume the worst ratio to prevent data being truncated

or insufficient buffer size situation. However, if you have specific knowledge of

your SQL Server database and do not want the expansion to occur, you can

specify

HS_KEEP_REMOTE_COLUMN_SIZE

parameter to suppress the expansion. Refer to

Initialization Parameters for more detail.

2.6 IPv6 Support

Besides full IPv6 support between Oracle databases and the gateway, IPv6 is also

supported between this gateway and SQL Server database.

Refer to the

HS_FDS_CONNECT_INFO

parameter in Initialization Parameters for more

detail.

2.7 Gateway Session IDLE Timeout

You can optionally choose to terminate long idle gateway sessions automatically with

the gateway parameter

HS_IDLE_TIMEOUT

Specifically, when a gateway session is idle for more than the specified time limit,

the gateway session is terminated with any pending update rolled back. Refer to the

HS_IDLE_TIMEOUT

parameter in Initialization Parameters for more detail.

2.8 Remote User-defined Function Support

User-defined functions in a remote non-Oracle database can be used in SQL

statements.

• Return Values and Stored Procedures

By default, all stored procedures and functions do not return a return value to the

user.

• Result Sets and Stored Procedures

The Oracle Database Gateway for SQL Server provides support for stored

procedures which return result sets.

See Also:

Oracle Database Heterogeneous Connectivity User's Guide for more

information about executing user-defined functions on a non-Oracle

database.

Chapter 2

Multi-byte Character Sets Ratio Suppression

2-4

2.8.1 Return Values and Stored Procedures

By default, all stored procedures and functions do not return a return value to the user.

To enable return values, set the

HS_FDS_PROC_IS_FUNC

parameter value to

TRUE

See Also:

Initialization Parameters for information about both editing the initialization

parameter file and the

HS_FDS_PROC_IS_FUNC

parameter.

Note:

If you set the

HS_FDS_PROC_IS_FUNC

gateway initialization parameter to

TRUE

you must change the syntax of the procedure execute statement for all

existing stored procedures.

In the following example, the employee name

JOHN SMYTHE

is passed to the SQL

Server stored procedure

REVISE_SALARY

. The stored procedure retrieves the salary

value from the SQL Server database to calculate a new yearly salary for

JOHN SMYTHE

The revised salary returned in

RESULT

is used to update

EMP

in a table of an Oracle

database:

DECLARE

INPUT VARCHAR2(15);

RESULT NUMBER(8,2);

BEGIN

INPUT := 'JOHN SMYTHE';

RESULT := REVISE_SALARY@MSQL(INPUT);

UPDATE EMP SET SAL = RESULT WHERE ENAME =: INPUT;

END;

The procedural feature automatically converts non-Oracle data types to and from

PL/SQL data types.

2.8.2 Result Sets and Stored Procedures

The Oracle Database Gateway for SQL Server provides support for stored procedures

which return result sets.

By default, all stored procedures and functions do not return a result set to the user. To

enable result sets, set the

HS_FDS_RESULTSET_SUPPORT

parameter value to

TRUE

Chapter 2

Remote User-defined Function Support

2-5

See Also:

Initialization Parameters for information about both editing the initialization

parameter file and the

HS_FDS_RESULTSET_SUPPORT

parameter. For further

information about Oracle support for result sets in non-Oracle databases see

Oracle Database Heterogeneous Connectivity User's Guide.

Note:

If you set the

HS_FDS_RESULTSET_SUPPORT

gateway initialization parameter to

TRUE

, then you must change the syntax of the procedure execute statement

for all existing stored procedures, else errors will occur.

When accessing stored procedures with result sets through the Oracle Database

Gateway for SQL Server, you will be in the sequential mode of Heterogeneous

Services.

The Oracle Database Gateway for SQL Server returns the following information to

Heterogeneous Services during procedure description:

• All the input arguments of the remote stored procedure

• None of the output arguments

• One out argument of type ref cursor (corresponding to the first result set returned

by the stored procedure)

Client programs have to use the virtual package function

DBMS_HS_RESULT_SET.GET_NEXT_RESULT_SET

to get the ref cursor for subsequent result

sets. The last result set returned is the out argument from the procedure.

The limitations of accessing result sets are the following:

• Result sets returned by a remote stored procedure have to be retrieved in the

order in which they were placed on the wire

• On execution of a stored procedure, all result sets returned by a previously

executed stored procedure will be closed (regardless of whether the data has

been completely retrieved or not)

In the following example, the SQL Server stored procedure is executed to fetch the

contents of the

emp

and

dept

tables from SQL Server:

create procedure REFCURPROC (@arg1 varchar(255), @arg2 varchar(255) output)

select @arg2 = @arg1

select * from EMP

select * from DEPT

This stored procedure assigns the input parameter arg1 to the output parameter arg2,

opens the query

SELECT * FROM EMP

in ref cursor rc1, and opens the query

SELECT *

FROM DEPT

in ref cursor rc2.

Chapter 2

Remote User-defined Function Support

2-6

• OCI Program Fetching from Result Sets in Sequential Mode

The following example shows OCI program fetching from result sets in sequential

mode.

• PL/SQL Program Fetching from Result Sets in Sequential Mode

Example of a PL/SQL program fetching from results sets in sequential mode.

2.8.2.1 OCI Program Fetching from Result Sets in Sequential Mode

The following example shows OCI program fetching from result sets in sequential

mode.

OCIEnv *ENVH;

OCISvcCtx *SVCH;

OCIStmt *STMH;

OCIError *ERRH;

OCIBind *BNDH[3];

OraText arg1[20];

OraText arg2[255];

OCIResult *rset;

OCIStmt *rstmt;

ub2 rcode[3];

ub2 rlens[3];

sb2 inds[3];

OraText *stmt = (OraText *) "begin refcurproc@MSQL(:1,:2,:3); end;";

OraText *n_rs_stm = (OraText *)

"begin :ret := DBMS_HS_RESULT_SET.GET_NEXT_RESULT_SET@MSQL; end;";

/* Prepare procedure call statement */

/* Handle Initialization code skipped */

OCIStmtPrepare(STMH, ERRH, stmt, strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);

/* Bind procedure arguments */

inds[0] = 0;

strcpy((char *) arg1, "Hello World");

rlens[0] = strlen(arg1);

OCIBindByPos(STMH, &BNDH[0], ERRH, 1, (dvoid *) arg1, 20, SQLT_CHR,

(dvoid *) &(inds[0]), &(rlens[0]), &(rcode[0]), 0, (ub4 *) 0,

OCI_DEFAULT);

inds[1] = -1;

OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) arg2, 20, SQLT_CHR,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]), 0, (ub4 *) 0,

OCI_DEFAULT);

inds[2] = 0;

rlens[2] = 0;

OCIDescriptorAlloc(ENVH, (dvoid **) &rset, OCI_DTYPE_RSET, 0, (dvoid **) 0);

OCIBindByPos(STMH, &BNDH[2], ERRH, 2, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[2]), &(rlens[2]), &(rcode[2]),

0, (ub4 *) 0, OCI_DEFAULT);

/* Execute procedure */

OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert result set to statement handle */

OCIResultSetToStmt(rset, ERRH);

rstmt = (OCIStmt *) rset;

Chapter 2

Remote User-defined Function Support

2-7

/* After this the user can fetch from rstmt */

/* Issue get_next_result_set call to get handle to next_result set */

/* Prepare Get next result set procedure call */

OCIStmtPrepare(STMH, ERRH, n_rs_stm, strlen(n_rs_stm), OCI_NTV_SYNTAX,

OCI_DEFAULT);

/* Bind return value */

OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]),

0, (ub4 *) 0, OCI_DEFAULT);

/* Execute statement to get next result set*/

OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert next result set to statement handle */

OCIResultSetToStmt(rset, ERRH);

rstmt = (OCIStmt *) rset;

/* Now rstmt will point to the second result set returned by the

remote stored procedure */

/* Repeat execution of get_next_result_set to get the output arguments */

2.8.2.2 PL/SQL Program Fetching from Result Sets in Sequential Mode

Example of a PL/SQL program fetching from results sets in sequential mode.

Assume that the table

loc_emp

is a local table exactly like the SQL Server

emp

table. The same assumption applies for

loc_dept

. The table

outargs

has columns

corresponding to the

out

arguments of the SQL Server stored procedure.

create table outargs (outarg varchar2(255), retval number);

create or replace package rcpackage is

type RCTYPE is ref cursor;

end rcpackage;

declare

rc1 rcpackage.rctype;

rec1 loc_emp%rowtype;

rc2 rcpackage.rctype;

rec2 loc_dept%rowtype;

rc3 rcpackage.rctype;

rec3 outargs%rowtype;

out_arg varchar2(255);

begin

-- Execute procedure

out_arg := null;

refcurproc@MSQL('Hello World', out_arg, rc1);

-- Fetch 20 rows from the remote emp table and insert them into loc_emp

for i in 1 .. 20 loop

fetch rc1 into rec1;

insert into loc_emp (rec1.empno, rec1.ename, rec1.job,

rec1.mgr, rec1.hiredate, rec1.sal, rec1.comm, rec1.deptno);

Chapter 2

Remote User-defined Function Support

2-8

end loop;

-- Close ref cursor

close rc1;

-- Get the next result set returned by the stored procedure

rc2 := dbms_hs_result_set.get_next_result_set@MSQL;

-- Fetch 5 rows from the remote dept table and insert them into loc_dept

for i in 1 .. 5 loop

fetch rc2 into rec2;

insert into loc_dept values (rec2.deptno, rec2.dname, rec2.loc);

end loop;

--Close ref cursor

close rc2;

-- Get the output arguments from the remote stored procedure

-- Since we are in sequential mode, they will be returned in the

-- form of a result set

rc3 := dbms_hs_result_set.get_next_result_set@MSQL;

-- Fetch them and insert them into the outargs table

fetch rc3 into rec3;

insert into outargs (rec3.outarg, rec3.retval);

-- Close ref cursor

close rc3;

end;

2.9 Database Compatibility Issues for SQL Server

SQL Server and Oracle databases function differently in some areas, causing

compatibility problems.

The compatibility issues are described in these topics.

• Implicit Transactions (Chained Mode)

The gateway supports the ANSI-standard implicit transactions.

• Column Definitions

By default, a SQL Server table column cannot contain null values unless

NULL

specified in the column definition.

• Naming Rules

These topics describe naming rule issues.

• Data Types

These topics describe data type issues.

• Queries

These topics describe query issues.

• Locking

The locking model for an SQL Server database differs significantly from the Oracle

model.

Chapter 2

Database Compatibility Issues for SQL Server

2-9

2.9.1 Implicit Transactions (Chained Mode)

The gateway supports the ANSI-standard implicit transactions.

SQL Server stored procedures must be written for this mode. Running implicit

transactions allows the gateway to extend the Oracle two-phase commit protection

to transactions updating Oracle and SQL Server databases.

2.9.2 Column Definitions

By default, a SQL Server table column cannot contain null values unless

NULL

specified in the column definition.

SQL Server assumes all columns cannot contain null values unless you set a SQL

Server option to override this default.

For an Oracle table, null values are allowed in a column unless

NOT NULL

is specified

in the column definition.

2.9.3 Naming Rules

These topics describe naming rule issues.

• Rules for Naming Objects

Oracle and SQL Server use different database object naming rules.

• Case Sensitivity

The Oracle database defaults to uppercase unless you surround identifiers with

double quote characters.

2.9.3.1 Rules for Naming Objects

Oracle and SQL Server use different database object naming rules.

For example, the maximum number of characters allowed for each object name can

be different. Also, the use of single and double quotation marks, case sensitivity, and

the use of alphanumeric characters can all be different.

See Also:

Oracle Database Reference and SQL Server documentation.

2.9.3.2 Case Sensitivity

The Oracle database defaults to uppercase unless you surround identifiers with double

quote characters.

For example, to refer to the SQL Server table called

emp

, enter the name with double

quote characters, as follows:

SQL> SELECT * FROM "emp"@MSQL;

Chapter 2

Database Compatibility Issues for SQL Server

2-10

However, to refer to the SQL Server table called

emp

owned by Scott from an Oracle

application, enter the following:

SQL> SELECT * FROM "Scott"."emp"@MSQL;

If the SQL Server table called

emp

is owned by

SCOTT

, a table owner name in

uppercase letters, you can enter the owner name without double quote characters,

as follows:

SQL> SELECT * FROM SCOTT."emp"@MSQL;

SQL> SELECT * FROM scott."emp"@MSQL;

Oracle recommends that you surround all SQL Server object names with double quote

characters and use the exact letter case for the object names as they appear in the

SQL Server data dictionary. This convention is not required when referring to the

supported Oracle data dictionary tables or views listed in Data Dictionary.

If existing applications cannot be changed according to these conventions, create

views in Oracle to associate SQL Server names to the correct letter case. For

example, to refer to the SQL Server table

emp

from an existing Oracle application

by using only uppercase names, define the following view:

SQL> CREATE VIEW EMP (EMPNO, ENAME, SAL, HIREDATE)

AS SELECT "empno", "ename", "sal", "hiredate"

FROM "emp"@MSQL;

With this view, the application can issue statements such as the following:

SQL> SELECT EMPNO, ENAME FROM EMP;

Using views is a workaround solution that duplicates data dictionary information

originating in the SQL Server data dictionary. You must be prepared to update the

Oracle view definitions whenever the data definitions for the corresponding tables are

changed in the SQL Server database.

2.9.4 Data Types

These topics describe data type issues.

• Binary Literal Notation

Oracle SQL uses hexadecimal digits surrounded by single quotes to express literal

values being compared or inserted into columns defined as data type

RAW

• Bind Variables With LONG Columns

The gateway does not support using bind variables to update columns of data type

LONG

• Data Type Conversion

SQL Server does not support implicit date conversions. Such conversions must be

explicit.

2.9.4.1 Binary Literal Notation

Oracle SQL uses hexadecimal digits surrounded by single quotes to express literal

values being compared or inserted into columns defined as data type

RAW

Chapter 2

Database Compatibility Issues for SQL Server

2-11

This notation is not converted to syntax compatible with the SQL Server

VARBINARY

and

BINARY

data types (a

followed by hexadecimal digits, surrounded by single

quotes).

For example, the following statement is not supported:

SQL> INSERT INTO BINARY_TAB@MSQL VALUES ('0xff')

Where

BINARY_TAB

contains a column of data type

VARBINARY

BINARY

. Use bind

variables when inserting into or updating

VARBINARY

and

BINARY

data types.

2.9.4.2 Bind Variables With LONG Columns

The gateway does not support using bind variables to update columns of data type

LONG

2.9.4.3 Data Type Conversion

SQL Server does not support implicit date conversions. Such conversions must be

explicit.

For example, the gateway issues an error for the following

SELECT

statement:

SELECT DATE_COL FROM TEST@MSQL WHERE DATE_COL = "1-JAN-2004";

To avoid problems with implicit conversions, add explicit conversions, as in the

following:

SELECT DATE_COL FROM TEST@MSQL WHERE DATE_COL = TO_DATE("1-JAN-2004")

See Also:

Data Type Conversion for more information about restrictions on data types.

2.9.5 Queries

These topics describe query issues.

• Row Selection

SQL Server evaluates a query condition for all selected rows before returning any

of the rows.

• Empty Strings

Oracle processes an empty string in a SQL statement as a null value. SQL Server

processes an empty string as an empty string.

• Empty Bind Variables

For

VARCHAR

bind variables, the gateway passes empty bind variables to the SQL

Server database as a

NULL

value.

2.9.5.1 Row Selection

SQL Server evaluates a query condition for all selected rows before returning any of

the rows.

Chapter 2

Database Compatibility Issues for SQL Server

2-12

If there is an error in the evaluation process for one or more rows, no rows are

returned even though the remaining rows satisfy the condition.

Oracle evaluates the query condition row-by-row and returns a row when the

evaluation is successful. Rows are returned until a row fails the evaluation.

2.9.5.2 Empty Strings

Oracle processes an empty string in a SQL statement as a null value. SQL Server

processes an empty string as an empty string.

When comparing an empty string the gateway passes literal empty strings to the SQL

Server database without any conversion. If you intended an empty string to represent

a null value, SQL Server does not process the statement that way; it uses the empty

string.

You can avoid this problem by using

NULL

IS NULL

in the SQL statement instead of

the empty string syntax, as in the following example:

SELECT * from "emp"@MSQL where "ename" IS NULL;

To select an empty string:

• For

VARCHAR

columns, the gateway returns an empty string to the Oracle database

NULL

value.

• For

CHAR

columns, the gateway returns the full size of the column with each

character as empty space (' ').

2.9.5.3 Empty Bind Variables

For

VARCHAR

bind variables, the gateway passes empty bind variables to the SQL

Server database as a

NULL

value.

2.9.6 Locking

The locking model for an SQL Server database differs significantly from the Oracle

model.

The gateway depends on the underlying SQL Server behavior, so the following

possible scenarios can affect Oracle applications that access SQL Server through the

gateway:

• Read access might block write access

• Write access might block read access

• Statement-level read consistency is not guaranteed

See Also:

SQL Server documentation for information about the SQL Server locking

model.

Chapter 2

Database Compatibility Issues for SQL Server

2-13

2.10 Known Restrictions

These topics describe known restrictions in Oracle Database Gateway for SQL Server

and includes suggestions for dealing with them when possible.

If you encounter incompatibility problems not listed in this section or in "Known

Problems", contact Oracle Support Services.

Note:

If you have any questions or concerns about the restrictions, contact Oracle

Support Services.

• Multiple Open Statements

Accessing SQL Server has the limitation that one open statement or cursor is

allowed for each connection. If a second statement or cursor needs to open in the

same transaction to access SQL Server, it requires a new connection.

• Transactional Integrity

The gateway cannot guarantee transactional integrity.

• Transaction Capability

The gateway does not support savepoints.

• COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open Cursors

Any

COMMIT

ROLLBACK

issued in a PL/SQL cursor loop closes all open cursors.

• Stored Procedures

The Oracle transaction manager or Oracle

COMMIT

ROLLBACK

commands

cannot control changes issued through stored procedures that embed commits

or rollbacks.

• Pass-Through Feature

If the SQL statements being passed through the gateway result in an implicit

commit at the SQL Server database, the Oracle transaction manager is unaware

of the commit and an Oracle

ROLLBACK

command cannot be used to roll back the

transaction.

• DDL Statements

SQL Server requires some DDL statements to be executed in their own

transaction, and only one DDL statement can be executed in a given transaction.

• SQL Syntax

These topics list restrictions on SQL syntax.

• Functions

This topic describes restrictions for using functions with Oracle Database Gateway

for SQL Server.

• SQL*Plus COPY Command with Lowercase Table Names

When using the SQL*Plus

COPY

command with lowercase table names, wrap the

table names in double quotation marks.

• Database Links

The gateway is not multithreaded and cannot support shared database links.

Chapter 2

Known Restrictions

2-14

2.10.1 Multiple Open Statements

Accessing SQL Server has the limitation that one open statement or cursor is allowed

for each connection. If a second statement or cursor needs to open in the same

transaction to access SQL Server, it requires a new connection.

Because of this limitation multiple open statements or cursors within the same

transaction can lock each other because they use different connections to SQL Server.

To avoid this restriction, issue a commit, or modify the logic, or both.

2.10.2 Transactional Integrity

The gateway cannot guarantee transactional integrity.

For example, in the following cases:

• When a statement that is processed by the gateway causes an implicit commit in

the target database

• When the target database is configured to work in Autocommit Mode

Note:

If you know that executing a particular statement causes an implicit commit

in the target database, Oracle strongly recommends that your ensure that the

statement is executed in its own transaction.

The gateway sets Autocommit Mode to Off when a connection is established to the

SQL Server database.

2.10.3 Transaction Capability

The gateway does not support savepoints.

If a distributed update transaction is under way involving the gateway, and a user

attempts to create a savepoint, the following error occurs:

ORA-02070: database dblink does not support savepoint in this context

By default, the gateway is configured as

COMMIT_CONFIRM

2.10.4 COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open

Cursors

Any

COMMIT

ROLLBACK

issued in a PL/SQL cursor loop closes all open cursors.

This can result in the following error:

ORA-1002: fetch out of sequence

To prevent this error, move the

COMMIT

ROLLBACK

statement outside the cursor loop.

Chapter 2

Known Restrictions

2-15

2.10.5 Stored Procedures

The Oracle transaction manager or Oracle

COMMIT

ROLLBACK

commands cannot

control changes issued through stored procedures that embed commits or rollbacks.

When accessing stored procedures with result sets through the Oracle Database

Gateway for SQL Server, you must work in the sequential mode of Heterogeneous

Services.

When accessing stored procedures with multiple result sets through the Oracle

Database Gateway for SQL Server, you must read all the result sets before continuing.

Output parameters of stored procedures must be initialized to an empty string.

2.10.6 Pass-Through Feature

If the SQL statements being passed through the gateway result in an implicit commit

at the SQL Server database, the Oracle transaction manager is unaware of the commit

and an Oracle

ROLLBACK

command cannot be used to roll back the transaction.

2.10.7 DDL Statements

SQL Server requires some DDL statements to be executed in their own transaction,

and only one DDL statement can be executed in a given transaction.

If you use these DDL statements in a SQL Server stored procedure and you execute

the stored procedure through the gateway using the procedural feature, or, if you

execute the DDL statements through the gateway using the pass-through feature,

an error condition might result. This is because the procedural feature and the

pass-through feature of the gateway cannot guarantee that the DDL statements are

executed in their own separate transaction.

The following SQL Server DDL statements can cause an error condition if you attempt

to pass them with the gateway pass-through feature, or if you execute a SQL Server

stored procedure that contains them:

•

ALTER DATABASE

•

CREATE DATABASE

•

CREATE INDEX

•

CREATE PROCEDURE

•

CREATE TABLE

•

CREATE VIEW

•

DISK INIT

•

DROP <object>

•

DUMP TRANSACTION

•

GRANT

•

LOAD DATABASE

•

LOAD TRANSACTION

Chapter 2

Known Restrictions

2-16

•

RECONFIGURE

•

REVOKE

•

SELECT INTO

•

TRUNCATE TABLE

•

UPDATE STATISTICS

See Also:

SQL Server documentation for more information about DDL statements.

2.10.8 SQL Syntax

These topics list restrictions on SQL syntax.

• WHERE CURRENT OF Clause

UPDATE

and

DELETE

statements with the

WHERE CURRENT OF

clause are not

supported by the gateway because they rely on the Oracle

ROWID

implementation.

• CONNECT BY Clause

The gateway does not support the

CONNECT BY

clause in a

SELECT

statement.

• Functions in Subqueries

Bind variables and expressions are not supported as operands in string functions

or mathematical functions, when part of subquery in an

INSERT

UPDATE

, or

DELETE

SQL statement.

• Parameters in Subqueries

Due to a limitation in SQL Server, you cannot use parameters in subqueries.

• Data Dictionary Table and Views in UPDATE Statement

Data dictionary tables and views in the

SET

clause of an

UPDATE

statement are not

supported.

• ROWID

The Oracle

ROWID

implementation is not supported.

• TO_DATE

TO_DATE

is a reserved word and cannot be used as a database identifier name.

• EXPLAIN PLAN Statement

The

EXPLAIN PLAN

statement is not supported.

See Also:

Supported SQL Syntax and Functions for more information about restrictions

on SQL syntax.

2.10.8.1 WHERE CURRENT OF Clause

UPDATE

and

DELETE

statements with the

WHERE CURRENT OF

clause are not supported

by the gateway because they rely on the Oracle

ROWID

implementation.

Chapter 2

Known Restrictions

2-17

To update or delete a specific row through the gateway, a condition style

WHERE

clause

must be used.

2.10.8.2 CONNECT BY Clause

The gateway does not support the

CONNECT BY

clause in a

SELECT

statement.

2.10.8.3 Functions in Subqueries

Bind variables and expressions are not supported as operands in string functions or

mathematical functions, when part of subquery in an

INSERT

UPDATE

, or

DELETE

SQL

statement.

2.10.8.4 Parameters in Subqueries

Due to a limitation in SQL Server, you cannot use parameters in subqueries.

2.10.8.5 Data Dictionary Table and Views in UPDATE Statement

Data dictionary tables and views in the

SET

clause of an

UPDATE

statement are not

supported.

2.10.8.6 ROWID

The Oracle

ROWID

implementation is not supported.

2.10.8.7 TO_DATE

TO_DATE

is a reserved word and cannot be used as a database identifier name.

2.10.8.8 EXPLAIN PLAN Statement

The

EXPLAIN PLAN

statement is not supported.

2.10.9 Functions

This topic describes restrictions for using functions with Oracle Database Gateway for

SQL Server.

The following restrictions apply to using functions:

• Unsupported functions cannot be used in statements that refer to

LONG

columns.

• When negative numbers are used as the second parameter in a

SUBSTR

function,

incorrect results are returned. This is due to incompatibility between the Oracle

SUBSTR

function and the equivalent in SQL Server.

2.10.10 SQL*Plus COPY Command with Lowercase Table Names

When using the SQL*Plus

COPY

command with lowercase table names, wrap the table

names in double quotation marks.

For example:

Chapter 2

Known Restrictions

2-18

copy from tkhouser/tkhouser@inst1 insert loc_tkhodept using select * from

"tkhodept"@holink2;

2.10.11 Database Links

The gateway is not multithreaded and cannot support shared database links.

Each gateway session spawns a separate gateway process and connections cannot

be shared.

2.11 Known Problems

These topics describe known problems with Oracle Database Gateway for SQL Server

and includes suggestions for correcting them when possible.

A current list of problems is available online. Contact your local Oracle office for

information about accessing the list.

• Encrypted Format Login

The

DBLINK_ENCRYPT_LOGIN

initialization parameter is obsolete.

• Date Arithmetic

SQL expressions that do not function correctly with the Oracle Database Gateway

for SQL Server.

• SQL Server IMAGE, TEXT and NTEXT Data Types

There are restrictions that apply when using the

IMAGE

TEXT

, and

NTEXT

data

types.

• String Functions

If you concatenate numeric literals using the "

" or

CONCAT

operator when using

the gateway to query a SQL Server database, the result is an arithmetic addition.

• Schema Names and PL/SQL

You must prefix a SQL Server database object with its schema name in a SQL

statement within a PL/SQL block.

• Data Dictionary Views and PL/SQL

You cannot refer to data dictionary views in SQL statements that are inside a

PL/SQL block.

• Stored Procedures

Return values of stored procedures that return result sets are incorrect.

2.11.1 Encrypted Format Login

The

DBLINK_ENCRYPT_LOGIN

initialization parameter is obsolete.

The Oracle9i database (Release 9.2 and earlier) supported an Oracle initialization

parameter,

DBLINK_ENCRYPT_LOGIN

. When this parameter is set to

TRUE

, the password

for the login user ID is not sent over the network.

If this parameter is set to

TRUE

in the initialization parameter file used by the Oracle9i

database, you must change the setting to

FALSE

, the default setting, to allow Oracle9i

to communicate with the gateway.

In the current release, the

DBLINK_ENCRYPT_LOGIN

initialization parameter is obsolete,

so you do not need to check it.

Chapter 2

Known Problems

2-19

2.11.2 Date Arithmetic

SQL expressions that do not function correctly with the Oracle Database Gateway for

SQL Server.

Statements with the following SQL expressions are sent to the SQL Server database

without any translation. Since SQL Server does not support these date arithmetic

functions, the statements return an error.

date + number

number + date

date - number

date1 - date2

2.11.3 SQL Server IMAGE, TEXT and NTEXT Data Types

There are restrictions that apply when using the

IMAGE

TEXT

, and

NTEXT

data types.

For example:

• An unsupported SQL function cannot be used in a SQL statement that accesses a

column defined as SQL Server data type

IMAGE

TEXT

, or

NTEXT

• You cannot use SQL*Plus to select data from a column defined as SQL Server

data type

IMAGE

TEXT

, or

NTEXT

when the data is greater than 80 characters in

length. Oracle recommends using Pro*C or Oracle Call Interface to access such

data in a SQL Server database.

•

IMAGE

TEXT

, and

NTEXT

data cannot be read through pass-through queries.

• If a SQL statement is accessing a table including an

IMAGE

TEXT

, or

NTEXT

column,

the statement will be sent to SQL Server as two separate statements. One

statement to access the

IMAGE

TEXT

NTEXT

column, and a second statement

for the other columns in the original statement.

The gateway does not support the PL/SQL function

COLUMN_VALUE_LONG

of the

DBMS_SQL

package.

See Also:

Supported SQL Syntax and Functions for more information about restrictions

on SQL syntax.

2.11.4 String Functions

If you concatenate numeric literals using the "

" or

CONCAT

operator when using the

gateway to query a SQL Server database, the result is an arithmetic addition.

For example, the result of the following statement is 18:

SQL> SELECT 9 || 9 FROM DUAL@MSQL;

The result is 99 when using Oracle to query an Oracle database.

Chapter 2

Known Problems

2-20

2.11.5 Schema Names and PL/SQL

You must prefix a SQL Server database object with its schema name in a SQL

statement within a PL/SQL block.

If you do not prefix a SQL Server database object with its schema name in a SQL

statement within a PL/SQL block, the following error message occurs:

ORA-6550 PLS-201 Identifier table_name must be declared.

Change the SQL statement to include the schema name of the object.

2.11.6 Data Dictionary Views and PL/SQL

You cannot refer to data dictionary views in SQL statements that are inside a PL/SQL

block.

2.11.7 Stored Procedures

Return values of stored procedures that return result sets are incorrect.

Chapter 2

Known Problems

2-21

Case Studies

The following case studies for SQL Server demonstrate some of the features of the

Oracle Database Gateway.

You can verify that the gateway is installed and operating correctly by using the

demonstration files included in the distribution media.

The demonstration files are automatically copied to disk when the gateway is installed.

• Installation Media Contents

This topic describes the installation media contents.

• Demonstration Files

After a successful gateway installation, use the demonstration files stored in the

See Also:

Oracle Database Reference for detailed descriptions of keywords,

parameters, and options.

B-1

B.1.1 DELETE

The

DELETE

statement is fully supported.

However, only Oracle functions supported by SQL Server can be used.

See Also:

Functions Supported by SQL Server for a list of supported functions.

B.1.2 INSERT

The

INSERT

statement is fully supported.

However, only Oracle functions supported by SQL Server can be used.

See Also:

Functions Supported by SQL Server for a list of supported functions.

B.1.3 SELECT

The

SELECT

statement is fully supported.

However, only Oracle functions supported by SQL Server can be used.

•

CONNECT BY

condition

•

NOWAIT

•

START WITH

condition

•

WHERE CURRENT

B.1.4 UPDATE

The

UPDATE

statement is fully supported.

However, only Oracle functions supported by SQL Server can be used.

See Also:

Functions Supported by SQL Server for a list of supported functions.

Appendix B

Supported SQL Statements

B-2

B.2 Oracle Functions

All functions are evaluated by the SQL Server database after the gateway has

converted them to SQL Server SQL equivalents.

The exception is the

TO_DATE

function, which is evaluated by the gateway.

• Functions Not Supported by SQL Server

Oracle SQL functions with no equivalent function in SQL Server are not supported

DELETE

INSERT

, or

UPDATE

statements, but are evaluated by the Oracle

database if the statement is a

SELECT

statement.

• Functions Supported by SQL Server

These topics describe the functions supported by Oracle Database Gateway for

SQL Server.

• Functions Supported by the Gateway

If an Oracle function has no equivalent function in SQL Server, the Oracle function

is not translated into the SQL statement and must be post-processed if the SQL

statement is a

SELECT

B.2.1 Functions Not Supported by SQL Server

Oracle SQL functions with no equivalent function in SQL Server are not supported in

DELETE

INSERT

, or

UPDATE

statements, but are evaluated by the Oracle database if the

statement is a

SELECT

statement.

That is, the Oracle database performs post-processing of

SELECT

statements sent to

the gateway.

If an unsupported function is used in a

DELETE

INSERT

, or

UPDATE

, statement, the

following Oracle error occurs:

ORA-02070: database db_link_name does not support function in this context

B.2.2 Functions Supported by SQL Server

These topics describe the functions supported by Oracle Database Gateway for SQL

Server.

The gateway translates the following Oracle database functions in SQL statements to

their equivalent SQL Server functions:

• Arithmetic Operators

Arithmetic operators supported by Oracle Database Gateway for SQL Server.

• Comparison Operators

Comparison operators supported by Oracle Database Gateway for SQL Server.

• Pattern Matching

Pattern matching using Oracle Database Gateway for SQL Server.

• Group Functions

Group functions supported by Oracle Database Gateway for SQL Server.

• String Functions

String functions supported by Oracle Database Gateway for SQL Server.

Appendix B

Oracle Functions

B-3

• Other Functions

Additional functions supported by Oracle Database Gateway for SQL Server.

B.2.2.1 Arithmetic Operators

Arithmetic operators supported by Oracle Database Gateway for SQL Server.

Oracle SQL Server

+ +

- -

* *

/ /

B.2.2.2 Comparison Operators

Comparison operators supported by Oracle Database Gateway for SQL Server.

Oracle SQL Server

= =

> >

< <

>= >=

<= <=

<>, !=, ^= <>

IS NOT NULL IS NOT NULL

IS NULL IS NULL

B.2.2.3 Pattern Matching

Pattern matching using Oracle Database Gateway for SQL Server.

Oracle SQL Server

LIKE LIKE

NOT LIKE NOT LIKE

B.2.2.4 Group Functions

Group functions supported by Oracle Database Gateway for SQL Server.

Oracle

SQL Server

AVG AVG

COUNT COUNT

MAX MAX

MIN MIN

Appendix B

Oracle Functions

B-4

Oracle SQL Server

SUM SUM

B.2.2.5 String Functions

String functions supported by Oracle Database Gateway for SQL Server.

Oracle SQL Server

||, CONCAT +

(expression1

expression2)

ASCII ASCII

CHR CHAR

INSTR

(with two arguments)

CHARINDEX

LENGTH () LEN ()

LENGTHB () DATALENGTH ()

LENGTHC () LEN ()

LOWER LOWER

LTRIM LTRIM

RTRIM RTRIM

SUBSTR

(second argument cannot be a

negative number)

SUBSTRING

UPPER UPPER

B.2.2.6 Other Functions

Additional functions supported by Oracle Database Gateway for SQL Server.

Oracle SQL Server

ABS ABS

CEIL CEILING

COS COS

EXP EXP

FLOOR FLOOR

LN LOG

LOG LOG10

MOD %

NOT NVL IS NOT NULL

NVL IS NULL

POWER POWER

ROUND ROUND

SIN SIN

SQRT SQRT

Appendix B

Oracle Functions

B-5

Oracle SQL Server

TAN TAN

B.2.3 Functions Supported by the Gateway

If an Oracle function has no equivalent function in SQL Server, the Oracle function

is not translated into the SQL statement and must be post-processed if the SQL

statement is a

SELECT

The gateway, however, does support the

TO_DATE

function equivalent in SQL Server,

as follows:

TO_DATE(date_string | date_column)

where:

•

date_string

is converted to a string with the following format:

yyyy-mm-dd hh:mi:ss.fff

Note:

Supply the date string with the same format as the result (that is,

yyyyy-

mm-dd hh:mi:ss.fff

•

date_column

is a column with a date data type. It is converted to a parameter with

a timestamp data type.

Appendix B

Oracle Functions

B-6

Data Dictionary

The Oracle Database Gateway for SQL Server translates a query that refers to an

Oracle database data dictionary table into a query that retrieves the data from SQL

Server system tables.

You perform queries on data dictionary tables over the database link in the same way

you query data dictionary tables in the Oracle database. The gateway data dictionary

is similar to the Oracle database data dictionary in appearance and use.

• Data Dictionary Support

The following topics describe the Oracle Database Gateway for SQL Server data

dictionary support.

• Data Dictionary Mapping

The tables in this section list Oracle data dictionary view names and the equivalent

SQL Server system tables used.

• Gateway Data Dictionary Descriptions

These topics describe the data dictionaries for Oracle Database Gateway for SQL

Server.

• ALL_CATALOG

ALL_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_COL_COMMENTS

ALL_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_CONS_COLUMNS

ALL_CONS_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_CONSTRAINTS

ALL_CONSTRAINTS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_IND_COLUMNS

ALL_IND_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_INDEXES

ALL_INDEXES

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_OBJECTS

ALL_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_TAB_COLUMNS

ALL_TAB_COLUMNS data dictionary for Oracle Database Gateway for SQL

Server.

• ALL_TAB_COMMENTS

ALL_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_TABLES

ALL_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

• ALL_USERS

ALL_USERS

data dictionary for Oracle Database Gateway for SQL Server.

C-1

• ALL_VIEWS

ALL_VIEWS

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_CATALOG

DBA_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_COL_COMMENTS

DBA_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_OBJECTS

DBA_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_TAB_COLUMNS

DBA_TAB_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_TAB_COMMENTS

DBA_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• DBA_TABLES

DBA_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

• DICT_COLUMNS

DICT_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• DICTIONARY

DICTIONARY

data dictionary for Oracle Database Gateway for SQL Server.

• DUAL

DUAL

data dictionary for Oracle Database Gateway for SQL Server.

• TABLE_PRIVILEGES

TABLE_PRIVILEGES

data dictionary for Oracle Database Gateway for SQL Server.

• USER_CATALOG

USER_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

• USER_COL_COMMENTS

USER_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_CONS_COLUMNS

USER_CONS_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_CONSTRAINTS

USER_CONSTRAINTS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_IND_COLUMNS

USER_IND_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_INDEXES

USER_INDEXES

data dictionary for Oracle Database Gateway for SQL Server.

• USER_OBJECTS

USER_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_TAB_COLUMNS

USER_TAB_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_TAB_COMMENTS

USER_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

• USER_TABLES

USER_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

• USER_USERS

USER_USERS

data dictionary for Oracle Database Gateway for SQL Server.

Appendix C

C-2

• USER_VIEWS

USER_VIEWS

data dictionary for Oracle Database Gateway for SQL Server.

C.1 Data Dictionary Support

The following topics describe the Oracle Database Gateway for SQL Server data

dictionary support.

• SQL Server System Tables

SQL Server data dictionary information is stored in the SQL Server database as

SQL Server system tables.

• Accessing the Gateway Data Dictionary

Accessing a gateway data dictionary table or view is identical to accessing a data

dictionary in an Oracle database.

• Direct Queries to SQL Server Tables

Queries issued directly to individual SQL Server system tables are allowed but

they return different results because the SQL Server system table column names

differ from those of the data dictionary view.

• Supported Views and Tables

The Oracle Database Gateway for SQL Server supports the following views and

tables.

C.1.1 SQL Server System Tables

SQL Server data dictionary information is stored in the SQL Server database as SQL

Server system tables.

All SQL Server system tables have names prefixed with

sys

. The SQL Server system

tables define the structure of a database. When you change data definitions, SQL

Server reads and modifies the SQL Server system tables to add information about the

user tables.

C.1.2 Accessing the Gateway Data Dictionary

Accessing a gateway data dictionary table or view is identical to accessing a data

dictionary in an Oracle database.

You issue a SQL

SELECT

statement specifying a database link. The Oracle database

data dictionary view and column names are used to access the gateway data

dictionary in an Oracle database. Synonyms of supported views are also acceptable.

For example, the following statement queries the data dictionary table

ALL_CATALOG

retrieve all table names in the SQL Server database:

SQL> SELECT * FROM "ALL_CATALOG"@MSQL;

When a data dictionary access query is issued, the gateway:

1. Maps the requested table, view, or synonym to one or more SQL Server system

table names. The gateway translates all data dictionary column names to their

corresponding SQL Server column names within the query. If the mapping

involves one SQL Server system table, the gateway translates the requested table

name to its corresponding SQL Server system table name within the query. If the

mapping involves multiple SQL Server system tables, the gateway constructs a

join in the query using the translated SQL Server system table names.

Appendix C

Data Dictionary Support

C-3

2. Sends the translated query to SQL Server.

3. Might convert the retrieved SQL Server data to give it the appearance of the

Oracle database data dictionary table.

4. Passes the data dictionary information from the translated SQL Server system

table to the Oracle database.

Note:

The values returned when querying the gateway data dictionary might

not be the same as the ones returned by the Oracle SQL*Plus

DESCRIBE

command.

C.1.3 Direct Queries to SQL Server Tables

Queries issued directly to individual SQL Server system tables are allowed but they

return different results because the SQL Server system table column names differ from

those of the data dictionary view.

Also, certain columns in an SQL Server system table cannot be used in data dictionary

processing.

C.1.4 Supported Views and Tables

The Oracle Database Gateway for SQL Server supports the following views and

tables.

ALL_CATALOG ALL_COL_COMMENTS

ALL_CONS_COLUMNS ALL_CONSTRAINTS

ALL_IND_COLUMNS ALL_INDEXES

ALL_OBJECTS ALL_TAB_COLUMNS

ALL_TAB_COMMENTS ALL_TABLES

ALL_USERS ALL_VIEWS

DBA_CATALOG DBA_COL_COMMENTS

DBA_OBJECTS DBA_TAB_COLUMNS

DBA_TAB_COMMENTS DBA_TABLES

DICT_COLUMNS DICTIONARY

Appendix C

Data Dictionary Support

C-4

DUAL TABLE_PRIVILEGES

USER_CATALOG USER_COL_COMMENTS

USER_CONS_COLUMNS USER_CONSTRAINTS

USER_IND_COLUMNS USER_INDEXES

USER_OBJECTS USER_TAB_COLUMNS

USER_TAB_COMMENTS USER_TABLES

USER_USERS USER_VIEWS

No other Oracle database data dictionary tables or views are supported. If you use a

view not on the list, you will receive the Oracle database error code for no more rows

available.

Queries through the gateway of any data dictionary table or view beginning with ALL_

can return rows from the SQL Server database even when access privileges for those

SQL Server objects have not been granted. When querying an Oracle database with

the Oracle data dictionary, rows are returned only for those objects you are permitted

to access.

C.2 Data Dictionary Mapping

The tables in this section list Oracle data dictionary view names and the equivalent

SQL Server system tables used.

A plus sign (+) indicates that a join operation is involved.

Table C-1 Oracle Data Dictionary View Names and SQL Server Equivalents

View Name SQL Server System Table Name

ALL_CATALOG sysusers

sysobjects

ALL_COL_COMMENTS sysusers

sysobjects

syscolumns

ALL_CONS_COLUMNS sp_pkeys

sp_fkeys

ALL_CONSTRAINTS sysusers

sysobjects

sysindexes

sysconstraints

sysreferences

ALL_IND_COLUMNS sysusers

sysindexes

syscolumns

ALL_INDEXES sysusers

sysindexes

sysobjects

ALL_OBJECTS sysusers

sysobjects

sysindexes

ALL_TAB_COLUMNS sysusers

sysobjects

syscolumns

ALL_TAB_COMMENTS sysusers

sysobjects

ALL_TABLES sysusers

sysobjects

ALL_USERS sysusers

Appendix C

Data Dictionary Mapping

C-5

Table C-1 (Cont.) Oracle Data Dictionary View Names and SQL Server

Equivalents

View Name SQL Server System Table Name

ALL_VIEWS sysusers

sysobjects

syscomments

DBA_CATALOG sysusers

sysobjects

DBA_COL_COMMENTS sysusers

sysobjects

syscolumns

DBA_OBJECTS sysusers

sysobjects

sysindexes

DBA_TABLES sysusers

sysobjects

DBA_TAB_COLUMNS sysusers

sysobjects

syscolumns

DBA_TAB_COMMENTS sysusers

sysobjects

DICT_COLUMNS sysobjects

syscolumns

DICTIONARY sysobjects

DUAL sysusers

TABLE_PRIVILEGES sysprotects

sysusers

sysobjects

USER_CATALOG sysusers

sysobjects

USER_COL_COMMENTS sysusers

sysobjects

syscolumns

USER_CONS_COLUMNS sp_pkeys

sp_fkeys

USER_CONSTRAINTS sysusers

sysobjects

sysindexes

sysconstraints

sysreferences

USER_IND_COLUMNS sysusers

sysindexes

syscolumns

USER_INDEXES sysusers

sysindexes

sysobjects

USER_OBJECTS sysusers

sysobjects

sysindexes

USER_TAB_COLUMNS sysusers

sysobjects

syscolumns

USER_TAB_COMMENTS sysusers

sysobjects

USER_TABLES sysusers

sysobjects

USER_USERS sysusers

USER_VIEWS sysusers

sysobjects

syscomments

• Default Column Values

There is a minor difference between the gateway data dictionary and a typical

Oracle database data dictionary.

C.2.1 Default Column Values

There is a minor difference between the gateway data dictionary and a typical Oracle

database data dictionary.

The Oracle database columns that are missing in a SQL Server system table are

filled with zeros, spaces, null values, not-applicable values (N.A.), or default values,

depending on the column type.

Appendix C

Data Dictionary Mapping

C-6

C.3 Gateway Data Dictionary Descriptions

These topics describe the data dictionaries for Oracle Database Gateway for SQL

Server.

The gateway data dictionary tables and views provide the following information:

• Name, data type, and width of each column

• The contents of columns with fixed values

They are described here with information retrieved by an Oracle SQL*Plus

DESCRIBE

command. The values in the

Null?

column might differ from the Oracle database data

dictionary tables and views. Any default value is shown to the right of an item, but this

is not information returned by

DESCRIBE

Note:

The column width of some columns in the translated data dictionary tables

would be different when the gateway connects to a SQL Server Version 7.0

database.

C.4 ALL_CATALOG

ALL_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

C.5 ALL_COL_COMMENTS

ALL_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

COMMENTS VARCHAR2(1)

C.6 ALL_CONS_COLUMNS

ALL_CONS_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Appendix C

Gateway Data Dictionary Descriptions

C-7

Name Type Value

OWNER VARCHAR2(256)

CONSTRAINT_NAME VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

POSITION NUMBER(5)

C.7 ALL_CONSTRAINTS

ALL_CONSTRAINTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

CONSTRAINT_NAME VARCHAR2(256)

CONSTRAINT_TYPE VARCHAR2(1)

" or "

" or

TABLE_NAME VARCHAR2(256)

SEARCH_CONDITION VARCHAR2(1) NULL

R_OWNER VARCHAR2(256)

R_CONSTRAINT_NAME VARCHAR2(256)

DELETE_RULE VARCHAR2(1) NULL

STATUS VARCHAR2(1) NULL

DEFERRABLE VARCHAR2(1) NULL

DEFERRED VARCHAR2(1) NULL

VALIDATED VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

BAD VARCHAR2(1) NULL

RELY VARCHAR2(1) NULL

LAST_CHANGE DATE

C.8 ALL_IND_COLUMNS

ALL_IND_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name

Type Value

INDEX_OWNER VARCHAR2(256)

INDEX_NAME VARCHAR2(256)

TABLE_OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

Appendix C

ALL_CONSTRAINTS

C-8

Name Type Value

COLUMN_POSITION NUMBER(3)

COLUMN_LENGTH NUMBER

Char_LENGTH NUMBER

DESCEND VARCHAR2(4)

C.9 ALL_INDEXES

ALL_INDEXES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

INDEX_NAME VARCHAR2(256)

INDEX_TYPE VARCHAR2(1) NULL

TABLE_OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR(7)

TABLE

" or

CLUSTER

UNIQUENESS VARCHAR2(1) NULL

COMPRESSION VARCHAR2(1) NULL

PREFIX_LENGTH NUMBER 0

TABLESPACE_NAME VARCHAR2(1) NULL

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

PCT_THRESHOLD NUMBER 0

INCLUDE_COLUMN NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

PCT_FREE NUMBER 0

LOGGING VARCHAR2(1) NULL

BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER 0

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

Appendix C

ALL_INDEXES

C-9

Name Type Value

CLUSTERING_FACTOR NUMBER 0

STATUS VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

PARTITIONED VARCHAR2(1) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARCHAR2(1) NULL

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(1) NULL

ITYP_NAME VARCHAR2(1) NULL

PARAMETERS VARCHAR2(1) NULL

GLOBAL_STATS VARCHAR2(1) NULL

DOMIDX_STATUS VARCHAR2(1) NULL

DOMIDX_OPSTATUS VARCHAR2(1) NULL

FUNCIDX_STATUS VARCHAR2(1) NULL

C.10 ALL_OBJECTS

ALL_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

OBJECT_NAME VARCHAR2(256)

SUBOBJECT_NAME VARCHAR2(1) NULL

OBJECT_ID NUMBER

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(9)

TABLE

" or "

VIEW

or "

INDEX

" or

PROCEDURE

CREATED DATE

LAST_DDL_TIME DATE

TIMESTAMP VARCHAR2(1) NULL

Appendix C

ALL_OBJECTS

C-10

Name Type Value

STATUS VARCHAR2(5)

VALID

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

C.11 ALL_TAB_COLUMNS

ALL_TAB_COLUMNS data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

DATA_TYPE VARCHAR2(9)

DATA_TYPE_MOD VARCHAR2(1) NULL

DATA_TYPE_OWNER VARCHAR2(1) NULL

DATA_LENGTH NUMBER

DATA_PRECISION NUMBER

DATA_SCALE NUMBER

NULLABLE VARCHAR2(1)

" or "

COLUMN_ID NUMBER(5)

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1) NULL

NUM_DISTINCT NUMBER 0

LOW_VALUE NUMBER 0

HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

CHARACTER_SET_NAME VARCHAR2(1) NULL

CHAR_COL_DEC_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

AVG_COL_LEN NUMBER 0

CHAR_LENGTH NUMBER

CHAR_USED VARCHAR2(1)

Appendix C

ALL_TAB_COLUMNS

C-11

Name Type Value

V80_FMT_IMAGE VARCHAR2(1)

DATA_UPGRADED VARCHAR2(1)

HISTOGRAM VARCHAR2(1)

C.12 ALL_TAB_COMMENTS

ALL_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

COMMENTS VARCHAR2(1) NULL

C.13 ALL_TABLES

ALL_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLESPACE_NAME VARCHAR2(1) NULL

CLUSTER_NAME VARCHAR2(1) NULL

IOT_NAME VARCHAR2(1) NULL

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(1) NULL

BACKED_UP VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

BLOCKS NUMBER 0

Appendix C

ALL_TAB_COMMENTS

C-12

Name Type Value

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

CACHE VARCHAR2(1) NULL

TABLE_LOCK VARCHAR2(1) NULL

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(1) NULL

IOT_TYPE VARCHAR2(1) NULL

TEMPORARY VARHCAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

NESTED VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

ROW_MOVEMENT VARCHAR2(1) NULL

GLOBAL_STATS VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARHCAR2(1) NULL

SKIP_CORRUPT VARCHAR2(1) NULL

MONITORING VARCHAR2(1) NULL

C.14 ALL_USERS

ALL_USERS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

USERNAME VARCHAR2(256)

USER_ID NUMBER(10)

CREATED DATE

C.15 ALL_VIEWS

ALL_VIEWS

data dictionary for Oracle Database Gateway for SQL Server.

Appendix C

ALL_USERS

C-13

Name Type Value

OWNER VARCHAR2(256)

VIEW_NAME VARCHAR2(256)

TEXT_LENGTH NUMBER 0

TEXT VARCHAR2(1)

TYPE_TEXT_LENGTH NUMBER 0

TYPE_TEXT VARCHAR2(1)

OID_TEXT_LENGTH NUMBER 0

OID_TEXT VARCHAR2(1)

VIEW_TYPE_OWNER VARCHAR2(1)

VIEW_TYPE VARCHAR2(1)

C.16 DBA_CATALOG

DBA_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

C.17 DBA_COL_COMMENTS

DBA_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

COMMENTS VARCHAR2(1) NULL

C.18 DBA_OBJECTS

DBA_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

Name

Type Value

OWNER VARCHAR2(256)

OBJECT_NAME VARCHAR2(256)

SUBOBJECT_NAME VARCHAR2(1) NULL

OBJECT_ID NUMBER

Appendix C

DBA_CATALOG

C-14

Name Type Value

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(9)

TABLE

" or "

VIEW

or "

INDEX

" or

PROCEDURE

CREATED DATE

LAST_DDL_TIME DATE

TIMESTAMP VARCHAR2(1) NULL

STATUS VARCHAR2(5) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

C.19 DBA_TAB_COLUMNS

DBA_TAB_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

DATA_TYPE VARCHAR2(9)

DATA_TYPE_MOD VARCHAR2(1) NULL

DATA_TYPE_OWNER VARCHAR2(1) NULL

DATA_LENGTH NUMBER

DATA_PRECISION NUMBER

DATA_SCALE NUMBER

NULLABLE VARCHAR2(1)

" or "

COLUMN_ID NUMBER(5)

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1) NULL

NUM_DISTINCT NUMBER 0

LOW_VALUE NUMBER 0

HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

CHARACTER_SET_NAME VARCHAR2(1) NULL

Appendix C

DBA_TAB_COLUMNS

C-15

Name Type Value

CHAR_COL_DEC_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

AVG_COL_LEN NUMBER 0

C.20 DBA_TAB_COMMENTS

DBA_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

COMMENTS VARCHAR2(1) NULL

C.21 DBA_TABLES

DBA_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLESPACE_NAME VARCHAR2(1) NULL

CLUSTER_NAME VARCHAR2(1) NULL

IOT_NAME VARCHAR2(1) NULL

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(1) NULL

BACKED_UP VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

Appendix C

DBA_TAB_COMMENTS

C-16

Name Type Value

BLOCKS NUMBER 0

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

CACHE VARCHAR2(1) NULL

TABLE_LOCK VARCHAR2(1) NULL

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(1) NULL

IOT_TYPE VARCHAR2(1) NULL

TEMPORARY VARHCAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

NESTED VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

ROW_MOVEMENT VARCHAR2(1) NULL

GLOBAL_STATS VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARHCAR2(1) NULL

SKIP_CORRUPT VARCHAR2(1) NULL

MONITORING VARCHAR2(1) NULL

C.22 DICT_COLUMNS

DICT_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

COMMENTS VARCHAR2(1) NULL

C.23 DICTIONARY

DICTIONARY

data dictionary for Oracle Database Gateway for SQL Server.

Appendix C

DICT_COLUMNS

C-17

Name Type Value

TABLE_NAME VARCHAR2(256)

COMMENTS VARCHAR2(1)

C.24 DUAL

DUAL

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

DUMMY VARCHAR2(1)

C.25 TABLE_PRIVILEGES

TABLE_PRIVILEGES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

GRANTEE VARCHAR2(256)

OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

GRANTOR VARCHAR2(256)

SELECT_PRIV VARCHAR2(1)

INSERT_PRIV VARCHAR2(1)

DELETE_PRIV VARCHAR2(1)

UPDATE_PRIV VARCHAR2(1)

REFERENCES_PRIV VARCHAR2(1)

ALTER_PRIV VARCHAR2(1)

INDEX_PRIV VARCHAR2(1)

CREATED DATE

C.26 USER_CATALOG

USER_CATALOG

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

C.27 USER_COL_COMMENTS

USER_COL_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Appendix C

DUAL

C-18

Name Type Value

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

COMMENTS VARCHAR2(1) NULL

C.28 USER_CONS_COLUMNS

USER_CONS_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(30)

CONSTRAINT_NAME VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

POSITION NUMBER(5)

C.29 USER_CONSTRAINTS

USER_CONSTRAINTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

OWNER VARCHAR2(256)

CONSTRAINT_NAME VARCHAR2(256)

CONSTRAINT_TYPE VARCHAR2(1)

" or "

" or

TABLE_NAME VARCHAR2(256)

SEARCH_CONDITION VARCHAR2(1) NULL

R_OWNER VARCHAR2(256)

R_CONSTRAINT_NAME VARCHAR2(256)

DELETE_RULE VARCHAR2(1) NULL

STATUS VARCHAR2(1) NULL

DEFERRABLE VARCHAR2(1) NULL

DEFERRED VARCHAR2(1) NULL

VALIDATED VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

BAD VARCHAR2(1) NULL

RELY VARCHAR2(1) NULL

LAST_CHANGE DATE

Appendix C

USER_CONS_COLUMNS

C-19

C.30 USER_IND_COLUMNS

USER_IND_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

INDEX_NAME VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

COLUMN_POSITION NUMBER(3)

COLUMN_LENGTH NUMBER

CHAR_LENGTH NUMBER

DESCEND VARCHAR2(4)

C.31 USER_INDEXES

USER_INDEXES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

INDEX_NAME VARCHAR2(256)

INDEX_TYPE VARCHAR2(1) NULL

TABLE_OWNER VARCHAR2(256)

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(7)

TABLE

" or

CLUSTER

UNIQUENESS VARCHAR2(1) NULL

COMPRESSION VARCHAR2(1) NULL

PREFIX_LENGTH NUMBER 0

TABLESPACE_NAME VARCHAR2(1) NULL

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

PCT_THRESHOLD NUMBER 0

INCLUDE_COLUMN NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

PCT_FREE NUMBER 0

Appendix C

USER_IND_COLUMNS

C-20

Name Type Value

LOGGING VARCHAR2(1) NULL

BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER 0

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

CLUSTERING_FACTOR NUMBER 0

STATUS VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

PARTITIONED VARCHAR2(1) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARHCAR2(1) NULL

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(1) NULL

ITYP_NAME VARCHAR2(1) NULL

PARAMETERS VARCHAR2(1) NULL

GLOBAL_STATS

ARCHAR2(1) NULL

DOMIDX_STATUS VARCHAR2(1) NULL

DOMIDX_OPSTATUS VARCHAR2(1) NULL

FUNCIDX_STATUS VARCHAR2(1) NULL

C.32 USER_OBJECTS

USER_OBJECTS

data dictionary for Oracle Database Gateway for SQL Server.

Name

Type Value

OBJECT_NAME VARCHAR2(256)

SUBOBJECT_NAME VARCHAR2(1) NULL

OBJECT_ID NUMBER

DATA_OBJECT_ID NUMBER 0

Appendix C

USER_OBJECTS

C-21

Name Type Value

OBJECT_TYPE VARCHAR2(9)

TABLE

" or "

VIEW

or "

INDEX

" or

PROCEDURE

CREATED DATE

LAST_DDL_TIME DATE

TIMESTAMP VARCHAR2(1) NULL

STATUS VARCHAR2(5)

VALID

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

C.33 USER_TAB_COLUMNS

USER_TAB_COLUMNS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

TABLE_NAME VARCHAR2(256)

COLUMN_NAME VARCHAR2(256)

DATA_TYPE VARCHAR2(9)

DATA_TYPE_MOD VARCHAR2(1) NULL

DATA_TYPE_OWNER VARCHAR2(1) NULL

DATA_LENGTH NUMBER

DATA_PRECISION NUMBER

DATA_SCALE NUMBER

NULLABLE VARCHAR2(1)

" or "

COLUMN_ID NUMBER(5)

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1) NULL

NUM_DISTINCT NUMBER 0

LOW_VALUE NUMBER 0

HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

CHARACTER_SET_NAME VARCHAR2(1) NULL

CHAR_COL_DECL_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(1) NULL

Appendix C

USER_TAB_COLUMNS

C-22

Name Type Value

USER_STATS VARCHAR2(1) NULL

AVG_COL_LEN NUMBER 0

CHAR_LENGTH NUMBER 0

CHAR_USED VARCHAR2(1)

V80_FMT_IMAGE VARCHAR2(1)

DATA_UPGRADED VARCHAR2(1)

HISTOGRAM VARCHAR2(1)

C.34 USER_TAB_COMMENTS

USER_TAB_COMMENTS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

TABLE_NAME VARCHAR2(256)

TABLE_TYPE VARCHAR2(5)

TABLE

" or "

VIEW

COMMENTS VARCHAR2(1) NULL

C.35 USER_TABLES

USER_TABLES

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

TABLE_NAME VARCHAR2(256)

TABLESPACE_NAME VARCHAR2(1) NULL

CLUSTER_NAME VARCHAR2(1) NULL

IOT_NAME VARCHAR2(1) NULL

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(1) NULL

BACKED_UP VARCHAR2(1) NULL

Appendix C

USER_TAB_COMMENTS

C-23

Name Type Value

NUM_ROWS NUMBER 0

BLOCKS NUMBER 0

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

CACHE VARCHAR2(1) NULL

TABLE_LOCK VARCHAR2(1) NULL

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(1) NULL

IOT_TYPE VARCHAR2(1) NULL

TEMPORARY VARHCAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

NESTED VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

ROW_MOVEMENT VARCHAR2(1) NULL

GLOBAL_STATS VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARCHAR2(1) NULL

SKIP_CORRUPT VARCHAR2(1) NULL

MONITORING VARCHAR2(1) NULL

C.36 USER_USERS

USER_USERS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

USERNAME VARCHAR2(256)

USER_ID NUMBER(5)

ACCOUNT_STATUS VARCHAR2(4)

OPEN

LOCK_DATE DATE NULL

EXPIRY_DATE DATE NULL

DEFAULT_TABLESPACE VARCHAR2(1) NULL

Appendix C

USER_USERS

C-24

Name Type Value

TEMPORARY_TABLESPACE VARCHAR2(1) NULL

CREATED DATE

INITIAL_RSRC_CONSUMER_GROUP VARCHAR2(1) NULL

EXTERNAL_NAME VARCHAR2(1) NULL

C.37 USER_VIEWS

USER_VIEWS

data dictionary for Oracle Database Gateway for SQL Server.

Name Type Value

VIEW_NAME VARCHAR2(256)

TEXT_LENGTH NUMBER 0

TEXT VARCHAR2(1)

TYPE_TEXT_LENGTH NUMBER 0

TYPE_TEXT VARCHAR2(1) NULL

OID_TEXT_LENGTH NUMBER 0

OID_TEXT VARCHAR2(1) NULL

VIEW_TYPE_OWNER VARCHAR2(1) NULL

VIEW_TYPE VARCHAR2(1) NULL

Appendix C

USER_VIEWS

C-25

Initialization Parameters

The Oracle database initialization parameters in the

init.ora

file are distinct from

gateway initialization parameters.

Set the gateway parameters in the initialization parameter file using an agent-specific

mechanism, or set them in the Oracle data dictionary using the

DBMS_HS

package. The

gateway initialization parameter file must be available when the gateway is started.

The following topics contain a list of the gateway initialization parameters that can be

set for each gateway and their description. The topics also describe the initialization

parameter file syntax.

• Initialization Parameter File Syntax

This topic describes the syntax for the initialization parameter file.

• HS_CALL_NAME

HS_CALL_NAME

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_DB_DOMAIN

HS_DB_DOMAIN

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_DB_INTERNAL_NAME

HS_DB_INTERNAL_NAME

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_DB_NAME

HS_DB_NAME

initialization parameter for Oracle Database Gateway for SQL Server.

• HS_DESCRIBE_CACHE_HWM

HS_DESCRIBE_CACHE_HWM

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_ARRAY_EXEC

HS_FDS_ARRAY_EXEC

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_FDS_AUTHENTICATE_METHOD

HS_FDS_AUTHENTICATE_METHOD

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_CONNECT_INFO

HS_FDS_CONNECT_INFO

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_DATE_MAPPING

HS_FDS_DATE_MAPPING

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_ENCRYPT_SESSION

HS_FDS_ENCRYPT_SESSION

initialization parameter for Oracle Database Gateway for

SQL Server.

D-1

• HS_FDS_FETCH_ROWS

HS_FDS_FETCH_ROWS

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_FDS_PROC_IS_FUNC

HS_FDS_PROC_IS_FUNC

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_RECOVERY_ACCOUNT

HS_FDS_RECOVERY_ACCOUNT

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_FDS_RECOVERY_PWD

HS_FDS_RECOVERY_PWD

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_REMOTE_DB_CHARSET

HS_FDS_REMOTE_DB_CHARSET

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_FDS_REPORT_REAL_AS_DOUBLE

HS_FDS_REPORT_REAL_AS_DOUBLE

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_RESULTSET_SUPPORT

HS_FDS_RESULTSET_SUPPORT

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_FDS_RSET_RETURN_ROWCOUNT

HS_FDS_RSET_RETURN_ROWCOUNT

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_SQLLEN_INTERPRETATION

HS_FDS_SQLLEN_INTERPRETATION

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_SUPPORT_STATISTICS

HS_FDS_SUPPORT_STATISTICS

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_TIMESTAMP_MAPPING

HS_FDS_TIMESTAMP_MAPPING

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_FDS_TRACE_LEVEL

HS_FDS_TRACE_LEVEL

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_TRANSACTION_ISOLATION

HS_FDS_TRANSACTION_ISOLATION

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_TRANSACTION_LOG

HS_FDS_TRANSACTION_LOG

initialization parameter for Oracle Database Gateway for

SQL Server.

• HS_FDS_TRUSTSTORE_FILE

HS_FDS_TRUSTSTORE_FILE

initialization parameter for Oracle Database Gateway for

SQL Server.

Appendix D

D-2

• HS_FDS_TRUSTSTORE_PASSWORD

HS_FDS_TRUSTSTORE_PASSWORD

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_FDS_VALIDATE_SERVER_CERT

HS_FDS_VALIDATE_SERVER_CERT

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_IDLE_TIMEOUT

HS_IDLE_TIMEOUT

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_KEEP_REMOTE_COLUMN_SIZE

HS_KEEP_REMOTE_COLUMN_SIZE

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_LANGUAGE

HS_LANGUAGE

initialization parameter for Oracle Database Gateway for SQL Server.

• HS_LONG_PIECE_TRANSFER_SIZE

HS_LONG_PIECE_TRANSFER_SIZE

initialization parameter for Oracle Database

Gateway for SQL Server.

• HS_NLS_LENGTH_SEMANTICS

HS_NLS_LENGTH_SEMANTICS

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_OPEN_CURSORS

HS_OPEN_CURSORS

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_RPC_FETCH_REBLOCKING

HS_RPC_FETCH_REBLOCKING

initialization parameter for Oracle Database Gateway

for SQL Server.

• HS_RPC_FETCH_SIZE

HS_RPC_FETCH_SIZE

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_TIME_ZONE

HS_TIME_ZONE

initialization parameter for Oracle Database Gateway for SQL

Server.

• HS_TRANSACTION_MODEL

HS_TRANSACTION_MODEL

initialization parameter for Oracle Database Gateway for

SQL Server.

• IFILE

IFILE

initialization parameter for Oracle Database Gateway for SQL Server.

D.1 Initialization Parameter File Syntax

This topic describes the syntax for the initialization parameter file.

• The file is a sequence of commands.

• Each command should start on a separate line.

• End of line is considered a command terminator (unless escaped with a

backslash).

Appendix D

Initialization Parameter File Syntax

D-3

• If there is a syntax error in an initialization parameter file, none of the settings take

effect.

• Set the parameter values as follows:

[SET][PRIVATE] parameter=value

where:

parameter

is an initialization parameter name. It is a string of characters starting

with a letter and consisting of letters, digits and underscores. Initialization

parameter names are case sensitive.

value

is the initialization parameter value. It is case sensitive. An initialization

parameter value is either:

– A string of characters that does not contain any backslashes, white space or

double quotation marks (")

– A quoted string beginning with a double quotation mark and ending with a

double quotation mark. The following can be used inside a quoted string:

* backslash (\) is the escape character

* \n inserts a new line

* \t inserts a tab

* \" inserts a double quotation mark

* \\ inserts a backslash

A backslash at the end of the line continues the string on the next line. If a

backslash precedes any other character then the backslash is ignored.

For example, to enable tracing for an agent, set the

HS_FDS_TRACE_LEVEL

initialization parameter as follows:

HS_FDS_TRACE_LEVEL=ON

SET

and

PRIVATE

are optional keywords. You cannot use either as an initialization

parameter name. Most parameters are needed only as initialization parameters, so

you usually do not need to use the

SET

PRIVATE

keywords. If you do not specify

either

SET

PRIVATE

, the parameter is used only as an initialization parameter for

the agent.

SET

specifies that, in addition to being used as an initialization parameter, the

parameter value is set as an environment variable for the agent process. Use

SET

for parameter values that the drivers or non-Oracle system need as environment

variables.

PRIVATE

specifies that the initialization parameter should be private to the agent

and should not be uploaded to the Oracle database. Most initialization parameters

should not be private. If, however, you are storing sensitive information like a

password in the initialization parameter file, then you may not want it uploaded

to the server because the initialization parameters and values are not encrypted

when uploaded. Making the initialization parameters private prevents the upload

from happening and they do not appear in dynamic performance views. Use

PRIVATE

for the initialization parameters only if the parameter value includes

sensitive information such as a user name or password.

Appendix D

Initialization Parameter File Syntax

D-4

SET PRIVATE

specifies that the parameter value is set as an environment variable

for the agent process and is also private (not transferred to the Oracle database,

not appearing in dynamic performance views or graphical user interfaces).

D.2 HS_CALL_NAME

HS_CALL_NAME

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value None

Range of values Not applicable

Specifies the remote functions that can be referenced in SQL statements. The value is

a list of remote functions and their owners, separated by semicolons, in the following

format:

owner_name.function_name

For example:

owner1.A1;owner2.A2;owner3.A3

If an owner name is not specified for a remote function, the default owner name

becomes the user name used to connect to the remote database (specified when the

Heterogeneous Services database link is created or taken from user session if not

specified in the DB link).

The entries for the owner names and the function names are case sensitive.

D.3 HS_DB_DOMAIN

HS_DB_DOMAIN

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value

WORLD

Range of values

199

characters

Specifies a unique network sub-address for a non-Oracle system. The

HS_DB_DOMAIN

initialization parameter is similar to the

DB_DOMAIN

initialization parameter, described in

the Oracle Database Reference. The

HS_DB_DOMAIN

initialization parameter is required

if you use the Oracle Names server. The

HS_DB_NAME

and

HS_DB_DOMAIN

initialization

parameters define the global name of the non-Oracle system.

Note:

The

HS_DB_NAME

and

HS_DB_DOMAIN

initialization parameters must combine to

form a unique address in a cooperative server environment.

Appendix D

HS_CALL_NAME

D-5

D.4 HS_DB_INTERNAL_NAME

HS_DB_INTERNAL_NAME

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default value

01010101

Range of values

hexadecimal characters

Specifies a unique hexadecimal number identifying the instance to which the

Heterogeneous Services agent is connected. This parameter's value is used as part

of a transaction ID when global name services are activated. Specifying a nonunique

number can cause problems when two-phase commit recovery actions are necessary

for a transaction.

D.5 HS_DB_NAME

HS_DB_NAME

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value

Range of values

characters

Specifies a unique alphanumeric name for the data store given to the non-Oracle

system. This name identifies the non-Oracle system within the cooperative server

environment. The

HS_DB_NAME

and

HS_DB_DOMAIN

initialization parameters define the

global name of the non-Oracle system.

D.6 HS_DESCRIBE_CACHE_HWM

HS_DESCRIBE_CACHE_HWM

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default value

100

Range of values

4000

Specifies the maximum number of entries in the describe cache used by

Heterogeneous Services. This limit is known as the describe cache high water mark.

The cache contains descriptions of the mapped tables that Heterogeneous Services

reuses so that it does not have to re-access the non-Oracle data store.

If you are accessing many mapped tables, increase the high water mark to improve

performance. Increasing the high water mark improves performance at the cost of

memory usage.

Appendix D

HS_DB_INTERNAL_NAME

D-6

D.7 HS_FDS_ARRAY_EXEC

HS_FDS_ARRAY_EXEC

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value

TRUE

Range of values

{TRUE|FALSE}

Syntax

HS_FDS_ARRAY_EXEC= {TRUE|FALSE}

If set to

TRUE

, the gateway will use array operations for insert, update, delete

statements containing binds against the remote data source. The array size is

determined by the value of the

HS_FDS_FETCH_ROWS

init parameter.

If set to

FALSE

, the gateway will not use array operations for insert, update, and delete

statements. Instead, a single statement will be issued for every value.

D.8 HS_FDS_AUTHENTICATE_METHOD

HS_FDS_AUTHENTICATE_METHOD

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default Value

CLEARTEXT

Range of values

{CLEARTEXT | ENCRYPT | ENCRYPT_BOTH | CLIENT}

Syntax

HS_FDS_AUTHENTICATE_METHOD= {CLEARTEXT | ENCRYPT |

ENCRYPT_BOTH | CLIENT}

Specifies the way in which user ID and password are sent to the remote DB2 server

and authenticated. Valid values are:

•

CLEARTEXT

: user ID and password are sent in clear text to server (default).

•

ENCRYPT

: password is sent encrypted to server.

•

ENCRYPT_BOTH

: user ID and password are sent encrypted to server.

•

CLIENT

: user ID is validated on the client side instead of by the server.

D.9 HS_FDS_CONNECT_INFO

HS_FDS_CONNECT_INFO

initialization parameter for Oracle Database Gateway for SQL

Server.

Property

Description

Default Value None

Range of Values Not applicable

Appendix D

HS_FDS_ARRAY_EXEC

D-7

HS_FDS_CONNECT_INFO

that describes the connection to the non-Oracle system.

The default initialization parameter file already has an entry for this parameter. The

syntax for

HS_FDS_CONNECT_INFO

for the gateway is as follows:

For UNIX:

HS_FDS_CONNECT_INFO=host_name[[:port_number]|/[instance_name]][/database_name]

where,

host_name

is the host name or IP address of the machine hosting the SQL

Server database,

port_number

is the port number of the SQL Server,

instance_name

is the instance of SQL Server running on the machine, and

database_name

is the SQL

Server database name.

Either of the variables

port_number

instance_name

can be used, but not both

together. Optionally, they both can be omitted. The variable

database_name

is always

optional. The slash (

) is required when a particular value is omitted. For example, all

of the following entries are valid:

HS_FDS_CONNECT_INFO=host_name/instance_name/database_name

HS_FDS_CONNECT_INFO=host_name//database_name

HS_FDS_CONNECT_INFO=host_name:port_name//database_name

HS_FDS_CONNECT_INFO=host_name/instance_name

HS_FDS_CONNECT_INFO=host_name

For Windows:

HS_FDS_CONNECT_INFO= host_name/[instance_name][/database_name]

where,

host_name

is the host name or IP address of the machine hosting the SQL

Server database,

instance_name

is the instance of SQL Server running on the

machine, and

database_name

is the SQL Server database name.

Both

instance_name

and

database_name

are optional. If

instance_name

is omitted and

database_name

is provided, the slash (

) is required. This can be shown as follows:

HS_FDS_CONNECT_INFO= host_name//database_name

This release supports IPv6 format, so you can enter IPv6 format in place of

hostname

but you need to wrap square brackets around the IPv6 specification.

For example:

HS_FDS_CONNECT_INFO=[2001:0db8:20c:f1ff:fec6:38af]:port_number/…

D.10 HS_FDS_DATE_MAPPING

HS_FDS_DATE_MAPPING

initialization parameter for Oracle Database Gateway for SQL

Server.

Property

Description

Default Value

DATE

Range of Values

DATE

CHAR

Syntax

HS_FDS_DATE_MAPPING={DATE|CHAR}

If set to

CHAR

, then non-oracle target date would be mapped to

CHAR(10)

. If set to

DATE

then non-Oracle target date would be mapped to Oracle date.

Appendix D

HS_FDS_DATE_MAPPING

D-8

D.11 HS_FDS_ENCRYPT_SESSION

HS_FDS_ENCRYPT_SESSION

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

NONE

Range of values

{NONE|SSL|NOTRUST_SSL}

Syntax

HS_FDS_ENCRYPT_SESSION = {NONE|SSL|NOTRUST_SSL}

Specifies the way the session to SQL Server is encrypted. Valid values are:

•

NONE

: data transmitted between the gateway and SQL Server is not encrypted.

(default).

•

SSL

: data transmitted between the gateway and SQL Server is encrypted using

SSL.

•

NOTRUST_SSL

: This option is equivalent to the SSL setting, with initialization

parameter

HS_FDS_VALIDATE_SERVER_CERT = DISABLED

D.12 HS_FDS_FETCH_ROWS

HS_FDS_FETCH_ROWS

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value

100

Range of Values

Any integer between

and

1000

Syntax

HS_FDS_FETCH_ROWS=num

HS_FDS_FETCH_ROWS

specifies the fetch array size. This is the number of rows

to be fetched from the non-Oracle database and to return to Oracle database

at one time. This parameter will be affected by the

HS_RPC_FETCH_SIZE

and

HS_RPC_FETCH_REBLOCKING

parameters.

D.13 HS_FDS_PROC_IS_FUNC

HS_FDS_PROC_IS_FUNC

initialization parameter for Oracle Database Gateway for SQL

Server.

Property

Description

Default Value

FALSE

Range of Values

TRUE

FALSE

Enables return values from functions. By default, all stored procedures and functions

do not return a return value to the user.

Appendix D

HS_FDS_ENCRYPT_SESSION

D-9

Note:

If you set this initialization parameter, you must change the syntax of the

procedure execute statement for all existing stored procedures to handle

return values.

D.14 HS_FDS_RECOVERY_ACCOUNT

HS_FDS_RECOVERY_ACCOUNT

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

RECOVER

Range of values Any valid user ID

Specifies the name of the recovery account used for the commit-confirm transaction

model. An account with user name and password must be set up at the non-

Oracle system. For more information about the commit-confirm model, see the

HS_TRANSACTION_MODEL

parameter.

The name of the recovery account is case sensitive.

D.15 HS_FDS_RECOVERY_PWD

HS_FDS_RECOVERY_PWD

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value

RECOVER

Range of values Any valid password

Specifies the password of the recovery account used for the commit-confirm

transaction model set up at the non-Oracle system. For more information about the

commit-confirm model, see the

HS_TRANSACTION_MODEL

parameter.

The name of the password of the recovery account is case sensitive.

D.16 HS_FDS_REMOTE_DB_CHARSET

HS_FDS_REMOTE_DB_CHARSET

initialization parameter for Oracle Database Gateway for

SQL Server.

Property

Description

Default Value None

Range of values Not applicable

Syntax

HS_FDS_REMOTE_DB_CHARSET

Appendix D

HS_FDS_RECOVERY_ACCOUNT

D-10

This parameter is valid only when

HS_LANGUAGE

is set to

AL32UTF8

and the gateway

runs on Windows. As more Oracle databases and non-Oracle databases use

Unicode as database character sets, it is preferable to also run the gateway in

Unicode character set. To do so, you must set

HS_LANGUAGE=AL32UTF8

. However,

when the gateway runs on Windows, the Microsoft ODBC Driver Manager

interface can exchange data only in the double-byte character set, UCS2.

This results in extra ratio expansion of described buffer and column sizes. To

compensate, the gateway can re-adjust the column size if

HS_FDS_REMOTE_DB_CHARSET

is set to the corresponding non-Oracle database character set. For example,

HS_FDS_REMOTE_DB_CHARSET=KO16KSC5601

D.17 HS_FDS_REPORT_REAL_AS_DOUBLE

HS_FDS_REPORT_REAL_AS_DOUBLE

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default Value

FALSE

Range of Values

TRUE

FALSE

Enables Oracle Database Gateway for SQL Server to treat

SINGLE FLOAT PRECISION

fields as

DOUBLE FLOAT PPRECISION

fields.

D.18 HS_FDS_RESULTSET_SUPPORT

HS_FDS_RESULTSET_SUPPORT

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

FALSE

Range of Values

TRUE

FALSE

Enables result sets to be returned from stored procedures. By default, all stored

procedures do not return a result set to the user.

Note:

If you set this initialization parameter, you must do the following:

• Change the syntax of the procedure execute statement for all existing

stored procedures, to handle result sets.

• Work in the sequential mode of Heterogeneous Services.

D.19 HS_FDS_RSET_RETURN_ROWCOUNT

HS_FDS_RSET_RETURN_ROWCOUNT

initialization parameter for Oracle Database Gateway

for SQL Server.

Appendix D

HS_FDS_REPORT_REAL_AS_DOUBLE

D-11

Property Description

Default Value

FALSE

Range of values

{TRUE|FALSE}

Syntax

HS_FDS_RSET_RETURN_ROWCOUNT= {TRUE|FALSE}

When set to

TRUE

, the gateway returns the row counts of DML statements that are

executed inside a stored procedure. The row count is returned as a single row, single

column result set of type signed integer.

When set to

FALSE

, the gateway skips the row counts of DML statements that are

executed inside a stored procedure. This is the default behavior, and it is the behavior

of 11.1 and older gateways.

D.20 HS_FDS_SQLLEN_INTERPRETATION

HS_FDS_SQLLEN_INTERPRETATION

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default Value

Range of values

{64|32}

Syntax

HS_FDS_SQLLEN_INTERPRETATION= {64|32}

This parameter is only valid for 64 bit platforms. ODBC standard specifies

SQLLEN

(of internal ODBC construct) being 64 bit on 64 bit platforms, but some ODBC

driver managers and drivers violate this convention, and implement it as 32 bit.

In order for the gateway to compensate their behavior, you need to specify

HS_FDS_SQLLEN_INTERPRETATION=32

if you use these types of driver managers and

driver.

D.21 HS_FDS_SUPPORT_STATISTICS

HS_FDS_SUPPORT_STATISTICS

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

TRUE

Range of values

{TRUE|FALSE}

Syntax

HS_FDS_SUPPORT_STATISTICS= {TRUE|FALSE}

We gather statistics from the non-Oracle database by default. You can

choose to disable the gathering of remote database statistics by setting the

HS_FDS_SUPPORT_STATISTICS

parameter to

FALSE

Appendix D

HS_FDS_SQLLEN_INTERPRETATION

D-12

D.22 HS_FDS_TIMESTAMP_MAPPING

HS_FDS_TIMESTAMP_MAPPING

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

DATE

Range of Values

CHAR

DATE

TIMESTAMP

Syntax

HS_FDS_TIMESTAMP_MAPPING={CHAR|DATE|TIMESTAMP}

If set to

CHAR

, then non-Oracle target timestamp would be mapped to

CHAR(26)

. If set

DATE

(default), then non-Oracle target timestamp would be mapped to Oracle

DATE

If set to

TIMESTAMP

, then non-Oracle target timestamp would be mapped to Oracle

TIMESTAMP

D.23 HS_FDS_TRACE_LEVEL

HS_FDS_TRACE_LEVEL

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value

OFF

Range of values

OFF

DEBUG

Specifies whether error tracing is turned on or off for gateway connectivity.

The following values are valid:

• OFF disables the tracing of error messages.

• ON enables the tracing of error messages that occur when you encounter

problems. The results are written by default to a gateway log file in LOG directory

where the gateway is installed.

• DEBUG enables the tracing of detailed error messages that can be used for

debugging.

D.24 HS_FDS_TRANSACTION_ISOLATION

HS_FDS_TRANSACTION_ISOLATION

initialization parameter for Oracle Database Gateway

for SQL Server.

Property

Description

Default Value

READ_COMMITTED

Range of Values

{

READ_UNCOMMITTED

READ_COMMITTED

REPEATABLE_READ

SERIALIZABLE

}

Appendix D

HS_FDS_TIMESTAMP_MAPPING

D-13

Property Description

Syntax

HS_FDS_ISOLATION_LEVEL={{READ_UNCOMMITTED|

READ_COMMITTED|REPEATABLE_READ|SERIALIZABLE}

HS_FDS_TRANSACTION_ISOLATION

specifies the isolation level that is used for the

transaction that the gateway opens on the non-Oracle database.

The isolation levels of

READ_UNCOMMITTED

READ_COMMITTED

REPEATABLE_READ

, and

SERIALIZABLE

are the four isolation levels defined in the SQL standard and adopted

by both ANSI and ISO/IEC. For additional information regarding them, see Oracle

Database Concepts.

Use caution when specifying an isolation level lower than the Oracle transaction

isolation level being used, as the gateway transaction will have different Preventable

Read Phenomena from what will occur in the Oracle database transaction.

D.25 HS_FDS_TRANSACTION_LOG

HS_FDS_TRANSACTION_LOG

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

HS_TRANSACTION_LOG

Range of Values Any valid table name

Specifies the name of the table created in the non-Oracle system for logging

transactions. For more information about the transaction model, see the

HS_TRANSACTION_MODEL

parameter.

D.26 HS_FDS_TRUSTSTORE_FILE

HS_FDS_TRUSTSTORE_FILE

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value none

Range of values

path to truststore file

Syntax

HS_FDS_TRUSTSTORE_FILE

= path to truststore file

Specifies the path that specifies the location of the truststore file. The truststore file

contains a list of the valid Certificate Authorities (CAs) that are trusted by the client

machine for SSL server authentication.

D.27 HS_FDS_TRUSTSTORE_PASSWORD

HS_FDS_TRUSTSTORE_PASSWORD

initialization parameter for Oracle Database Gateway

for SQL Server.

Appendix D

HS_FDS_TRANSACTION_LOG

D-14

Property Description

Default Value none

Range of values

password

Syntax

HS_FDS_TRUSTSTORE_PASSWORD

password

Specifies the password required to access the truststore.

D.28 HS_FDS_VALIDATE_SERVER_CERT

HS_FDS_VALIDATE_SERVER_CERT

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default Value

ENABLED

Range of values

{ENABLED|DISABLED}

Syntax

HS_FDS_VALIDATE_SERVER_CERT = {ENABLED|DISABLED}

Specifies whether the driver validates the certificate that is sent by the database server

when SSL encryption is enabled through

HS_FDS_ENCRYPT_SESSION

. When using SSL

server authentication, any certificate sent by the server must be issued by a trusted

Certificate Authority. Valid values are:

•

ENABLED

: the gateway validates the certificate that is sent by the database

server. Any certificate from the server must be issued by a trusted Certificate

Authority in the truststore file. The truststore information is specified using

the

HS_FDS_TRUSTSTORE_FILE

and

HS_FDS_TRUSTSTORE_PASSWORD

initialization

parameters.

•

DISABLED

: the gateway does not validate the certificate that is sent by the

database server.

D.29 HS_IDLE_TIMEOUT

HS_IDLE_TIMEOUT

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value 0 (no timeout)

Range of Values 0-9999 (minutes)

Syntax

HS_IDLE_TIMEOUT=num

This feature is only available for Oracle Net TCP protocol. When there is no activity for

a connected gateway session for this specified time period, the gateway session would

be terminated automatically with pending update (if any) rolled back.

Appendix D

HS_FDS_VALIDATE_SERVER_CERT

D-15

D.30 HS_KEEP_REMOTE_COLUMN_SIZE

HS_KEEP_REMOTE_COLUMN_SIZE

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default Value

OFF

Range of Values

OFF | LOCAL | REMOTE | ALL

Syntax

HS_KEEP_REMOTE_COLUMN_SIZE = OFF | LOCAL |

REMOTE | ALL

Parameter type String

HS_KEEP_REMOTE_COLUMN_SIZE

specifies whether to suppress ratio expansion when

computing the length of

(VAR)CHAR

data types during data conversion from the non-

Oracle database to the gateway, and then to the Oracle database. When it is set

REMOTE

, the expansion is suppressed between the non-Oracle database and the

gateway. When it is set to

LOCAL

, the expansion is suppressed between the gateway

and the Oracle database. When it is set to

ALL

, the expansion is suppressed from the

non-Oracle database to the Oracle database.

When the parameter is set, the expansion is suppressed when reporting the

remote column size, calculating the implicit resulting buffer size, and instantiating

in the local Oracle database. This has effect only for remote column size from

non-Oracle database to Oracle database. If the gateway runs on Windows and

HS_LANGUAGE=AL32UTF8

, then you must not specify this parameter, as it would influence

other ratio related parameter operation. It has no effect for calculating ratio for data

moving from Oracle database to non-Oracle database through gateway during

INSERT

UPDATE

, or

DELETE

D.31 HS_LANGUAGE

HS_LANGUAGE

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value

System-specific

Range of values

Any valid language name (up to

255

characters)

Provides Heterogeneous Services with character set, language, and territory

information of the non-Oracle data source. The value must use the following format:

language[_territory.character_set]

Note:

The globalization support initialization parameters affect error messages, the

data for the SQL Service, and parameters in distributed external procedures.

Appendix D

HS_KEEP_REMOTE_COLUMN_SIZE

D-16

• Character Sets

The character sets of the Oracle database and the non-Oracle data source are the

same.

• Language

The language component of the

HS_LANGUAGE

initialization parameter.

• Territory

The territory component of the

HS_LANGUAGE

initialization parameter specifies the

conventions for day and week numbering, default date format, decimal character

and group separator, and ISO and local currency symbols.

D.31.1 Character Sets

The character sets of the Oracle database and the non-Oracle data source are the

same.

In almost all cases,

HS_LANGUAGE

should be set exactly the same as Oracle database

character set for optimal character set mapping and performance. If they are not

the same, Heterogeneous Services attempts to translate the character set of the

non-Oracle data source to the Oracle database character set, and back again. The

translation can degrade performance. In some cases, Heterogeneous Services cannot

translate a character from one character set to another.

Note:

The specified character set must be a superset of the operating system

character set on the platform where the agent is installed.

As more Oracle databases and non-Oracle databases use Unicode as database

character sets, it is preferable to also run the gateway in Unicode character set. To

do so, you must set

HS_LANGUAGE=AL32UTF8

. However, when the gateway runs on

Windows, the Microsoft ODBC Driver Manager interface can exchange data only in

the double-byte character set, UCS2. This results in extra ratio expansion of described

buffer and column sizes. Refer to HS_FDS_REMOTE_DB_CHARSET for instruction

on how to adjust to correct sizes.

D.31.2 Language

The language component of the

HS_LANGUAGE

initialization parameter.

• Day and month names of dates

• AD, BC, PM, and AM symbols for date and time

• Default sorting mechanism

Note that Oracle does not determine the language for error messages for the

generic Heterogeneous Services messages (

ORA-25000

through

ORA-28000

). These

are controlled by the session settings in the Oracle database.

Appendix D

HS_LANGUAGE

D-17

D.31.3 Territory

The territory component of the

HS_LANGUAGE

initialization parameter specifies the

conventions for day and week numbering, default date format, decimal character and

group separator, and ISO and local currency symbols.

Note that the level of globalization support between the Oracle database and the

non-Oracle data source depends on how the gateway is implemented.

D.32 HS_LONG_PIECE_TRANSFER_SIZE

HS_LONG_PIECE_TRANSFER_SIZE

initialization parameter for Oracle Database Gateway

for SQL Server.

Property Description

Default value

64 KB

Range of values

Any value up to

2 GB

Sets the size of the piece of

LONG

data being transferred. A smaller piece size means

less memory requirement, but more round-trips to fetch all the data. A larger piece size

means fewer round-trips, but more of a memory requirement to store the intermediate

pieces internally. Thus, the initialization parameter can be used to tune a system

for the best performance, with the best trade-off between round-trips and memory

requirements, and network latency or response time.

D.33 HS_NLS_LENGTH_SEMANTICS

HS_NLS_LENGTH_SEMANTICS

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default Value

BYTE

Range of Values

BYTE | CHAR

Syntax

HS_NLS_LENGTH_SEMANTICS = { BYTE | CHAR }

This release of gateway has Character Semantics functionality equivalent to

the Oracle Database Character Semantics, that is,

NLS_LENGTH_SEMANTICS

. When

HS_NLS_LENGTH_SEMANTICS

is set to

CHAR

, the

(VAR)CHAR

columns of SQL Server

database are to be interpreted as having

CHAR

semantics. The only situation the

gateway does not honor the

HS_NLS_LENGTH_SEMANTICS=CHAR

setting is when both

Oracle database and the gateway are on the same multi-byte character set

D.34 HS_OPEN_CURSORS

HS_OPEN_CURSORS

initialization parameter for Oracle Database Gateway for SQL

Server.

Appendix D

HS_LONG_PIECE_TRANSFER_SIZE

D-18

Property Description

Default value

Range of values

to the value of Oracle's

OPEN_CURSORS

initialization parameter

Defines the maximum number of cursors that can be open on one connection to a

non-Oracle system instance.

The value never exceeds the number of open cursors in the Oracle database.

Therefore, setting the same value as the

OPEN_CURSORS

initialization parameter in the

Oracle database is recommended.

D.35 HS_RPC_FETCH_REBLOCKING

HS_RPC_FETCH_REBLOCKING

initialization parameter for Oracle Database Gateway for

SQL Server.

Property Description

Default value

Range of values

OFF

Controls whether Heterogeneous Services attempts to optimize performance of

data transfer between the Oracle database and the Heterogeneous Services agent

connected to the non-Oracle data store.

The following values are possible:

•

OFF

disables reblocking of fetched data so that data is immediately sent from agent

to server.

•

enables reblocking, which means that data fetched from the non-Oracle system

is buffered in the agent and is not sent to the Oracle database until the amount

of fetched data is equal to or higher than the value of

HS_RPC_FETCH_SIZE

initialization parameter. However, any buffered data is returned immediately when

a fetch indicates that no more data exists or when the non-Oracle system reports

an error.

D.36 HS_RPC_FETCH_SIZE

HS_RPC_FETCH_SIZE

initialization parameter for Oracle Database Gateway for SQL

Server.

Property

Description

Default value

50000

Range of values

10000000

Tunes internal data buffering to optimize the data transfer rate between the server and

the agent process.

Increasing the value can reduce the number of network round-trips needed to transfer

a given amount of data, but also tends to increase data bandwidth and to reduce

Appendix D

HS_RPC_FETCH_REBLOCKING

D-19

latency as measured between issuing a query and completion of all fetches for the

query. Nevertheless, increasing the fetch size can increase latency for the initial fetch

results of a query, because the first fetch results are not transmitted until additional

data is available.

D.37 HS_TIME_ZONE

HS_TIME_ZONE

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value for

'[+|-]hh:mm'

Derived from the

NLS_TERRITORY

initialization parameter

Range of values for

'[+|-]hh:mm'

Any valid datetime format mask

Specifies the default local time zone displacement for the current SQL session. The

format mask, [+|-]hh:mm, is specified to indicate the hours and minutes before or after

UTC (Coordinated Universal Time—formerly Greenwich Mean Time). For example:

HS_TIME_ZONE = [+ | -] hh:mm

D.38 HS_TRANSACTION_MODEL

HS_TRANSACTION_MODEL

initialization parameter for Oracle Database Gateway for SQL

Server.

Property Description

Default Value

COMMIT_CONFIRM

Range of Values

COMMIT_CONFIRM

READ_ONLY

SINGLE_SITE

READ_ONLY_AUTOCOMMIT

SINGLE_SITE_AUTOCOMMIT

Specifies the type of transaction model that is used when the non-Oracle database is

updated by a transaction.

The following values are possible:

•

COMMIT_CONFIRM

provides read and write access to the non-Oracle database and

allows the gateway to be part of a distributed update. To use the commit-confirm

model, the following items must be created in the non-Oracle database:

– Transaction log table. The default table name is

HS_TRANSACTION_LOG

. A

different name can be set using the

HS_FDS_TRANSACTION_LOG

parameter. The

transaction log table must be granted

SELECT

DELETE

, and

INSERT

privileges

set to public.

– Recovery account. The account name is assigned with the

HS_FDS_RECOVERY_ACCOUNT

parameter.

– Recovery account password. The password is assigned with the

HS_FDS_RECOVERY_PWD

parameter.

•

READ_ONLY

provides read access to the non-Oracle database.

Appendix D

HS_TIME_ZONE

D-20

•

SINGLE_SITE

provides read and write access to the non-Oracle database.

However, the gateway cannot participate in distributed updates.

•

READ_ONLY_AUTOCOMMIT

provides read only access to the non-Oracle database that

does not use logging.

•

SINGLE_SITE_AUTOCOMMIT

provides read and write access to the non-Oracle

database without logging. The gateway cannot participate in distributed updates.

Moreover, any update to the non-Oracle database is committed immediately.

D.39 IFILE

IFILE

initialization parameter for Oracle Database Gateway for SQL Server.

Property Description

Default value None

Range of values Valid parameter file names

Use the

IFILE

initialization parameter to embed another initialization file within the

current initialization file. The value should be an absolute path and should not contain

environment variables. The three levels of nesting limit do not apply.

See Also:

Oracle Database Reference

Appendix D

IFILE

D-21

Index

ALTER statement, B-1

Arithmetic operators, B-4

BIGINT data type, A-1

BINARY data type, A-1

BIT data type, A-1

Case rules, 2-10

Case studies, 3-1

Chained mode, 2-10

CHAR data type, A-1

character sets

Heterogeneous Services, D-17

COMMIT

restrictions, 2-15

Comparison operators, B-4

CONCAT operator, 2-20

CONNECT BY clause, 2-18

COPY command, 2-18

CREATE statement, B-1

Cursor loops

restrictions, 2-15

Data definition language, B-1

Data dictionary

views, C-4

Data type

BIGINT, A-1

BINARY, A-1

BIT, A-1

CHAR, A-1

conversion, 2-12

DATE, A-1

DATETIME, A-1

DECIMAL, A-1

FLOAT, A-1

Data type (continued)

IMAGE, A-1

LONG RAW, A-1

MONEY, A-1

NCHAR, A-1

NUMBER, A-1

NUMERIC, A-1

NVARCHAR, A-1

RAW, A-1

REAL, A-1

SMALL DATETIME, A-1

SMALL MONEY, A-1

SMALLINT, A-1

TIMESTAMP, A-1

TINYINT, A-1

VARBINARY, 2-19, A-1

VARCHAR, A-1

DATE data type, A-1

DATETIME data type, A-1

DECIMAL data type, A-1

DELETE statement, 3-6, B-2, B-3

demonstration build SQL script, 3-2

Demonstration files, 3-2

Demonstration tables, 3-3

Demonstration tables build SQL script, 3-3

describe cache high water mark

definition, D-6

DROP statement, B-1

Encrypted format login, 2-19

Error messages

error tracing, D-13

Errors

ORA-02070, 2-15

Executing Stored Procedures, 3-7

fetch array size, with HS_FDS_FETCH_ROWS,

D-9

FLOAT data type, A-1

Functions in SQL, 2-3

Index-1

Gateway

case studies, 3-1

data dictionary tables, C-3

pass-through feature, 2-2, 2-16

supported functions, B-1

supported SQL syntax, B-1

globalization support

Heterogeneous Services, D-16

GRANT statement, B-1

Group functions, B-4

Heterogeneous Services

defining maximum number of open cursors,

D-18

optimizing data transfer, D-19

setting global name, D-6

specifying cache high water mark, D-6

tuning internal data buffering, D-19

tuning LONG data transfer, D-18

Hexadecimal notation, 2-11

HS_CALL_NAME initialization parameter, D-5

HS_DB_NAME initialization parameter, D-6

HS_DESCRIBE_CACHE_HWM initialization

parameter, D-6

HS_FDS_CONNECT_INFO, D-7

HS_FDS_FETCH_ROWS parameter, D-9

HS_FDS_PROC_IS_FUNC initialization

parameter, D-9

HS_FDS_RECOVERY_PWD initialization

parameter, D-11

HS_FDS_RESULTSET_SUPPORT initialization

parameter, D-11

HS_FDS_TRACE_LEVEL initialization

parameter, D-13

enabling agent tracing, D-3

HS_FDS_TRANSACTION_ISOLATIONparamete

r, D-13

HS_FDS_TRANSACTION_LOG initialization

parameter, D-14

HS_IDLE_TIMEOUT initialization parameter,

D-15

HS_KEEP_REMOTE_COLUMN_SIZE

initialization parameter, D-16

HS_LANGUAGE initialization parameter, D-16

HS_LONG_PIECE_TRANSFER_SIZE

initialization parameter, D-18

HS_NLS_LENGTH_SEMANTICS initialization

parameter, D-18

HS_OPEN_CURSORS initialization parameter,

D-18

HS_RPC_FETCH_REBLOCKING initialization

parameter, D-19

HS_RPC_FETCH_SIZE initialization parameter,

D-19

HS_TIME_ZONE initialization parameter, D-20

IFILE initialization parameter, D-21

IMAGE data type, A-1

Initialization parameter file

customizing, D-1

INSERT statement, 3-6, B-2, B-3

isolation level,

HS_FDS_TRANSACTION_ISOLATION,

D-13

Known restrictions, 2-14

Locking, database, 2-13

LONG RAW data type, A-1

MONEY data type, A-1

NCHAR data type, A-1

NULL values, 2-10

NUMBER data type, A-1

NUMERIC data type, A-1

NVARCHAR data type, A-1

NVL function, 3-5

Objects, naming rules, 2-10

ORA-02070, 2-15

parameters

gateway initialization file

HS_FDS_FETCH_ROWS, D-9

HS_FDS_TRANSACTION_ISOLATION,

D-13

Pass-Through Feature, 3-6

Passing commands to database, 2-16

Pattern Matching, B-4

Index

Index-2

PL/SQL, 2-21

RAW data type, A-1

REAL data type, A-1

remote

HS_FDS_TRANSACTION_ISOLATION,

D-13

remote functions

referenced in SQL statements, D-5

ROLLBACK

restrictions, 2-15

ROWID, 2-17, 2-18

savepoint support, 2-15

SELECT statement, 3-7, B-2, C-3

SMALL DATETIME data type, A-1

SMALLINT data type, A-1

SQL

statements,

HS_FDS_TRANSACTION_ISOLATION,

D-13

Stored procedures, 2-16, 2-21

running in chained mode, 2-10

Stored procedures (continued)

Stored procedures in SQL Server, 2-3

String functions, B-5

SUM function, 3-5

TIMESTAMP data type, A-1

TINYINT data type, A-1

Transaction modes, 2-10

transactional capability, 2-15

transactional integrity, 2-15

TRUNCATE statement, B-1

Two-phase commit, 2-15

UPDATE statement, 2-18, 3-6, 3-7, B-2, B-3

VARBINARY data type, 2-19, A-1

VARCHAR data type, A-1

WHERE CURRENT OF clause, 2-17

Index

Index-3