Oracle8i Distributed Database Systems

How Oracle8i Distributed Database Systems is Organized

Conventions Used in This Guide

Your Comments Are Welcome

Oracle's Distributed Database Architecture

Clients and Servers

The Network

Databases and Database Links

Database Links

Schema Object Name Resolution

Connecting Between Oracle Server Versions

Distributed Databases and Distributed Processing

Distributed Databases and Database Replication

Heterogeneous Distributed Databases

Heterogeneous Services

Heterogeneous Services Agents

Features

Developing Distributed Database Applications

Distributed Query Optimization

Remote and Distributed SQL Statements

Remote Procedure Calls (RPCs)

Remote and Distributed Transactions

Transparency in a Distributed Database System

Administering an Oracle Distributed Database System

Site Autonomy

Distributed Database Security

Tools for Administering Oracle Distributed Databases

Enterprise Manager

Third-Party Administration Tools

SNMP Support

National Language Support

Global Database Names and Global Object Names

Types of Database Links

Private, Public, and Global Database Links

Security Options for Database Links

Shared Database Links

Connection Qualifiers

Database Link Resolution

Schema Object Name Resolution

Views, Synonyms, Procedures and Global Name Resolution

Dropping a Database Link

Listing Available Database Links

Limiting the Number of Active Database Links

Techniques for Location Transparency

Views and Location Transparency

Synonyms and Location Transparency

Procedures and Location Transparency

Statement Transparency

Restrictions

Values for Environmentally-Dependent SQL Functions

Shared SQL for Remote and Distributed Statements

Distributed Transaction Management

The Prepare and Commit Phases

Prepare Phase

Commit Phase

The Session Tree

Clients

Servers and Database Servers

Local Coordinators

The Global Coordinator

The Commit Point Site

A Case Study

The Scenario

The Process

Coordination of System Change Numbers

Read-Only Distributed Transactions

Limiting the Number of Distributed Transactions Per Node

Troubleshooting Distributed Transaction Problems

Failures that Interrupt Two-Phase Commit

Failures that Prevent Data Access

Manually Overriding In-Doubt Transactions

Manual Override Example

Step 1: Record User Feedback

Step 2: Query DBA_2PC_PENDING

Step 3: Query DBA_2PC_NEIGHBORS

Manually Checking the Status of Pending Transactions at SALES.ACME.COM

Manually Checking the Status of Pending Transactions at HQ.ACME.COM:

Step 4: Check for Mixed Outcome

The Pending Transaction Table (DBA_2PC_PENDING)

Manually Committing In-Doubt Transactions

Forcing a Commit or Rollback in Enterprise Manager

Manually Committing or Rolling Back In-Doubt Transactions

Changing Connection Hold Time

Setting a Limit on Distributed Transactions

Testing Distributed Transaction Recovery Features

Forcing a Distributed Transaction to Fail

The Recoverer (RECO) Background Process

Disabling and Enabling RECO

Factors Affecting the Distribution of an Application's Data

Controlling Connections Established by Database Links

Referential Integrity in a Distributed System

Distributed Queries

Tuning Distributed Queries

Cost Based Optimization

Extend Cost Based Optimization with Hints

Verifying Optimization

Handling Errors in Remote Procedures

What is Heterogeneous Services?

Heterogeneous Services Agents

The Services provided by Heterogeneous Services

Transaction Service

SQL Service

Procedural Service

Using Heterogeneous Services

Heterogeneous Services Process Architecture

Process Architecture for Distributed External Procedures

Setting up access to Non-Oracle Systems

Install the Heterogeneous Services Data Dictionary

Set Up Environment to Access Heterogeneous Services Agents

Create the Database Link to the Non-Oracle System

Test the Connection

Register Distributed External Procedures (Optional)

Structure of the Heterogeneous Services Data Dictionary

The Data Dictionary Views

General Data Dictionary Views for Heterogeneous Services

Views for the Transaction Service

Views for the SQL Service

Views for Distributed External Procedures

The DBMS_HS Package

Setting Initialization Parameters

Unsetting Initialization Parameters

Security for Distributed External Procedures

Agent Self-Registration

Advantages of Agent Self-Registration

How Does Agent Self-Registration Work?

Oracle Server Initialization Parameter HS_AUTOREGISTER

Application Development with Heterogeneous Services

Pass-Through SQL

Considerations When Using Pass-Through SQL

Executing Pass-Through SQL Statements

Executing Queries

Bulk Fetch

Array Fetch Using the OCI, an Oracle Precompiler, or Another Tool

Array Fetch Between an Oracle8i Server and the Agent

Array Fetch Between the Agent and the Non-Oracle Datastore

Reblocking

HS_COMMIT_POINT_STRENGTH

Purpose

HS_DB_DOMAIN

Purpose

HS_DB_INTERNAL_NAME

Purpose

HS_DB_NAME

Purpose

HS_DESCRIBE_CACHE_HWM

HS_LANGUAGE

HS_NLS_DATE_FORMAT

Purpose

HS_NLS_DATE_LANGUAGE

Purpose

HS_NLS_NCHAR

HS_OPEN_CURSORS

Purpose

HS_ROWID_CACHE_SIZE

Purpose

HS_RPC_FETCH_REBLOCKING

Purpose

HS_FDS_FETCH_ROWS

Purpose

HS_RPC_FETCH_SIZE

Purpose

DBMS_HS.CREATE_FDS_INST

Purpose

Interface description

See Also

DBMS_HS.CREATE_INST_INIT

Purpose

Interface description

See Also

DBMS_HS.DROP_FDS_INST

Purpose

Interface Description

See Also

DBMS_HS.DROP_INST_INIT

Purpose

Interface description

See Also

DBMS_HS_PASSTHROUGH.BIND_VARIABLE

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.BIND_VARIABLE_RAW

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.BIND_OUT_VARIABLE

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.BIND_OUT_VARIABLE_RAW

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.BIND_INOUT_VARIABLE

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.BIND_INOUT_VARIABLE_RAW

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.CLOSE_CURSOR

Purpose

Interface Description

See Also

DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.EXECUTE_NON_QUERY

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.FETCH_ROW

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.GET_VALUE

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.GET_VALUE_RAW

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.OPEN_CURSOR

Purpose

Interface Description

Purity Level

See Also

DBMS_HS_PASSTHROUGH.PARSE

Purpose

Interface Description

Purity Level

See Also

DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_ ALL

Purpose

Interface Description

Purity Level

See Also

DBMS_DISTRIBUTED_TRUST_ADMIN.ALLOW_ ALL

Purpose

Interface Description

Purity Level

See Also

DBMS_DISTRIBUTED_TRUST_ADMIN.ALLOW_SERVER
(SERVER IN VARCHAR2)

Purpose

Interface Description

Purity Level

DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_SERVER
(SERVER IN VARCHAR2)

Purpose

Interface Description

Purity Level

Contents

Title and Copyright Information

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Preface

1 Distributed Database Concepts

2 Distributed Database Administration

3 Distributed Transactions

4 Distributed Database System Application Development

5 Understanding Oracle Heterogeneous Services

6 Administering Oracle Heterogeneous Services

7 Application Development with Heterogeneous Services

A Heterogeneous Services Initialization Parameters

B DBMS_HS Package Reference

C DBMS_HS_PASSTHROUGH for Pass-Through SQL

D DBMS_DISTRIBUTED_TRUST_ADMIN Package Reference

Index