Preface

Oracle Heterogeneous Services describes implementation issues for Oracle8i Heterogeneous Services. It also introduces the tools and utilities available to assist you in implementing and using this feature.

This preface contains these topics:

Audience
Organization
Related Documentation
Conventions

See Also:
Getting to Know Oracle8i for information about the differences between Oracle8i and the Oracle8i Enterprise Edition.

Audience

Oracle Heterogeneous Services is intended for database administrators who administer or plan to administer a distributed database system involving either Oracle to Oracle database links or Oracle to non-Oracle database links.

To use this document, you need to be familiar with:

Relational database concepts and basic database administration as described in Oracle8i Concepts and the Oracle8i Administrator's Guide.
The operating system environment under which database administrators are running Oracle.

Organization

This document contains:

Chapter 1, "Heterogeneous Services Concepts" provides an overview of Oracle Heterogeneous Services.

Chapter 2, "Managing Heterogeneous Services" explains how to implement and maintain Heterogeneous Services using an Oracle Transparent Gateway.

Chapter 3, "Generic Connectivity" provides the information you need to connect to non-Oracle datastores through ODBC or OLE DB.

Chapter 4, "Developing Applications with Heterogeneous Services" provides the information you will need to develop applications that use Oracle Heterogeneous Services.

Appendix A, "Heterogeneous Services Initialization Parameters" lists all Heterogeneous Services-specific initialization parameters and their values.

Appendix B, "Heterogeneous Services Data Dictionary Views" lists the data dictionary views that are available through Heterogeneous Services mapping.

Appendix C, "DBMS_HS_PASSTHROUGH for Pass-Through SQL" describes the procedures and functions in the package DBMS_HS_PASSTHROUGH for pass-through SQL of Heterogeneous Services.

Appendix D, "Data Dictionary Translation for Generic Connectivity" explains and lists data dictionary translations for generic connectivity.

Appendix E, "Datatype Mapping" explains how datatypes are mapped for ODBC and OLE DB compliant data sources.

Conventions

This section describes the conventions used in the text and code examples of the this documentation set. It describes:

Conventions in Text

We use various conventions in text to help you more quickly identify special terms. The following table describes those conventions and provides examples of their use.

Convention Meaning Example

Bold

Bold typeface indicates terms that are defined in the text or terms that appear in a glossary, or both.

The C datatypes such as ub4, sword, or OCINumber are valid.
When you specify this clause, you create an index-organized table.

Italics

Italic typeface indicates book titles, emphasis, syntax clauses, or placeholders.

Oracle8i Concepts
You can specify the parallel_clause.
Run Uold_release.SQL where old_release refers to the release you installed prior to upgrading.

UPPERCASE monospace (fixed-width font)

Uppercase monospace typeface indicates elements supplied by the system. Such elements include parameters, privileges, datatypes, RMAN keywords, SQL keywords, SQL*Plus or utility commands, packages and methods, as well as system-supplied column names, database objects and structures, user names, and roles.

You can specify this clause only for a NUMBER column.
You can back up the database using the BACKUP command.
Query the TABLE_NAME column in the USER_TABLES data dictionary view.
Specify the ROLLBACK_SEGMENTS parameter.
Use the DBMS_STATS.GENERATE_STATS procedure.

lowercase monospace (fixed-width font)

Lowercase monospace typeface indicates executables and sample user-supplied elements. Such elements include computer and database names, net service names, and connect identifiers, as well as user-supplied database objects and structures, column names, packages and classes, user names and roles, program units, and parameter values.

Enter sqlplus to open SQL*Plus.
The department_id, department_name, and location_id columns are in the hr.departments table.
Set the QUERY_REWRITE_ENABLED initialization parameter to true.
Connect as oe user.

Convention	Meaning	Example
Bold	Bold typeface indicates terms that are defined in the text or terms that appear in a glossary, or both.	The C datatypes such as ub4, sword, or OCINumber are valid. When you specify this clause, you create an index-organized table.
Italics	Italic typeface indicates book titles, emphasis, syntax clauses, or placeholders.	Oracle8i Concepts You can specify the parallel_clause. Run `U``old_release``.SQL` where old_release refers to the release you installed prior to upgrading.
UPPERCASE monospace (fixed-width font)	Uppercase monospace typeface indicates elements supplied by the system. Such elements include parameters, privileges, datatypes, RMAN keywords, SQL keywords, SQL*Plus or utility commands, packages and methods, as well as system-supplied column names, database objects and structures, user names, and roles.	You can specify this clause only for a `NUMBER` column. You can back up the database using the `BACKUP` command. Query the `TABLE_NAME` column in the `USER_TABLES` data dictionary view. Specify the `ROLLBACK_SEGMENTS` parameter. Use the `DBMS_STATS`.`GENERATE_STATS` procedure.
lowercase monospace (fixed-width font)	Lowercase monospace typeface indicates executables and sample user-supplied elements. Such elements include computer and database names, net service names, and connect identifiers, as well as user-supplied database objects and structures, column names, packages and classes, user names and roles, program units, and parameter values.	Enter `sqlplus` to open SQL*Plus. The `department_id`, `department_name`, and `location_id` columns are in the `hr.departments` table. Set the `QUERY_REWRITE_ENABLED` initialization parameter to `true.` Connect as `oe` user.

Conventions in Code Examples

Code examples illustrate SQL, PL/SQL, SQL*Plus, or other command-line statements. They are displayed in a monospace (fixed-width) font and separated from normal text as shown in this example:

SELECT username FROM dba_users WHERE username = 'MIGRATE';

The following table describes typographic conventions used in code examples and provides examples of their use.

Convention Meaning Example

[ ]

Brackets enclose one or more optional items. Do not enter the brackets.

DECIMAL (digits [ , precision ])

{ }

Braces enclose two or more items, one of which is required. Do not enter the braces.

{ENABLE | DISABLE}

|

A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the vertical bar.

{ENABLE | DISABLE}
[COMPRESS | NOCOMPRESS]

...

Horizontal ellipsis points indicate either:

That we have omitted parts of the code that are not directly related to the example

That you can repeat a portion of the code

CREATE TABLE ... AS subquery;

SELECT col1, col2, ... , coln FROM employees;

.
.
.

Vertical ellipsis points indicate that we have omitted several lines of code not directly related to the example.

Other notation

You must enter symbols other than brackets, braces, vertical bars, and ellipsis points as it is shown.

acctbal NUMBER(11,2);
acct CONSTANT NUMBER(4) := 3;

Italics

Italicized text indicates variables for which you must supply particular values.

CONNECT SYSTEM/system_password

UPPERCASE

Uppercase typeface indicates elements supplied by the system. We show these terms in uppercase in order to distinguish them from terms you define. Unless terms appear in brackets, enter them in the order and with the spelling shown. However, because these terms are not case sensitive, you can enter them in lowercase.

SELECT last_name, employee_id FROM employees;
SELECT * FROM USER_TABLES;
DROP TABLE hr.employees;

lowercase

Lowercase typeface indicates programmatic elements that you supply. For example, lowercase indicates names of tables, columns, or files.

SELECT last_name, employee_id FROM employees;
sqlplus hr/hr

Convention	Meaning	Example
[ ]	Brackets enclose one or more optional items. Do not enter the brackets.	`DECIMAL (digits [ , precision ])`
{ }	Braces enclose two or more items, one of which is required. Do not enter the braces.	`{ENABLE \| DISABLE}`
\|	A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the vertical bar.	`{ENABLE \| DISABLE}` `[COMPRESS \| NOCOMPRESS]`
`...`	Horizontal ellipsis points indicate either: That we have omitted parts of the code that are not directly related to the example That you can repeat a portion of the code	`CREATE TABLE ... AS subquery;` `SELECT col1, col2, ... , col``n` `FROM employees;`
. . .	Vertical ellipsis points indicate that we have omitted several lines of code not directly related to the example.
Other notation	You must enter symbols other than brackets, braces, vertical bars, and ellipsis points as it is shown.	`acctbal NUMBER(11,2);` `acct CONSTANT NUMBER(4) := 3;`
`Italics`	Italicized text indicates variables for which you must supply particular values.	`CONNECT SYSTEM/``system_password`
`UPPERCASE`	Uppercase typeface indicates elements supplied by the system. We show these terms in uppercase in order to distinguish them from terms you define. Unless terms appear in brackets, enter them in the order and with the spelling shown. However, because these terms are not case sensitive, you can enter them in lowercase.	`SELECT last_name, employee_id FROM employees;` `SELECT * FROM USER_TABLES;` `DROP TABLE hr.employees;`
`lowercase`	Lowercase typeface indicates programmatic elements that you supply. For example, lowercase indicates names of tables, columns, or files.	`SELECT last_name, employee_id FROM employees;` `sqlplus hr/hr`