Oracle8i Distributed Database Systems -- Contents

What's New in Oracle8i?

Release 8.1.6

Release 8.1.5

Structure

Changes to This Book

Audience

Knowledge Assumed of the Reader

How to Use This Guide

Conventions Used in This Guide

Your Comments Are Welcome

Distributed Database Architecture

Homogenous Distributed Database Systems

Heterogeneous Distributed Database Systems

Client/Server Database Architecture

Database Links

What Are Database Links?

Why Use Database Links?

Global Database Names in Database Links

Names for Database Links

Types of Database Links

Users of Database Links

Creation of Database Links: Examples

Schema Objects and Database Links

Database Link Restrictions

Distributed Database Administration

Site Autonomy

Distributed Database Security

Auditing Database Links

Administration Tools

Transaction Processing in a Distributed System

Remote SQL Statements

Distributed SQL Statements

Shared SQL for Remote and Distributed Statements

Remote Transactions

Distributed Transactions

Two-Phase Commit Mechanism

Database Link Name Resolution

Schema Object Name Resolution

Global Name Resolution in Views, Synonyms, and Procedures

Distributed Database Application Development

Transparency in a Distributed Database System

Remote Procedure Calls (RPCs)

Distributed Query Optimization

National Language Support

Client/Server Environment

Homogeneous Distributed Environment

Heterogeneous Distributed Environment

Managing Global Names in a Distributed System

Understanding How Global Database Names Are Formed

Determining Whether Global Naming Is Enforced

Viewing a Global Database Name

Changing the Domain in a Global Database Name

Changing a Global Database Name: Scenario

Creating Database Links

Obtaining Privileges Necessary for Creating Database Links

Specifying Link Types

Specifying Link Users

Using Connection Qualifiers to Specify Service Names Within Link Names

Creating Shared Database Links

Determining Whether to Use Shared Database Links

Creating Shared Database Links

Configuring Shared Database Links

Managing Database Links

Closing Database Links

Dropping Database Links

Limiting the Number of Active Database Link Connections

Viewing Information About Database Links

Determining Which Links Are in the Database

Determining Which Link Connections Are Open

Creating Location Transparency

Using Views to Create Location Transparency

Using Synonyms to Create Location Transparency

Using Procedures to Create Location Transparency

Managing Statement Transparency

Understanding Transparency Restrictions

Managing a Distributed Database: Scenarios

Creating a Public Fixed User Database Link

Creating a Public Fixed User Shared Database Link

Creating a Public Connected User Database Link

Creating a Public Connected User Shared Database Link

Creating a Public Current User Database Link

Managing the Distribution of an Application's Data

Controlling Connections Established by Database Links

Maintaining Referential Integrity in a Distributed System

Tuning Distributed Queries

Using Collocated Inline Views

Using Cost-Based Optimization

Using Hints

Analyzing the Execution Plan

Handling Errors in Remote Procedures

What Are Distributed Transactions?

Supported Types of Distributed Transactions

Session Trees for Distributed Transactions

Two-Phase Commit Mechanism

Session Trees for Distributed Transactions

Two-Phase Commit Mechanism

Prepare Phase

Commit Phase

Forget Phase

In-Doubt Transactions

Automatic Resolution of In-Doubt Transactions

Manual Resolution of In-Doubt Transactions

Relevance of System Change Numbers for In-Doubt Transactions

Distributed Transaction Processing: Case Study

Stage 1: Client Application Issues DML Statements

Stage 2: Oracle Determines Commit Point Site

Stage 3: Global Coordinator Sends Prepare Response

Stage 4: Commit Point Site Commits

Stage 5: Commit Point Site Informs Global Coordinator of Commit

Stage 6: Global and Local Coordinators Tell All Nodes to Commit

Stage 7: Global Coordinator and Commit Point Site Complete the Commit

Setting Distributed Transaction Initialization Parameters

Limiting the Number of Distributed Transactions

Specifying the Lock Timeout Interval

Specifying the Interval for Holding Open Connections

Specifying the Commit Point Strength of a Node

Viewing Information About Distributed Transactions

Determining the ID Number and Status of Prepared Transactions

Tracing the Session Tree of In-Doubt Transactions

Deciding How to Handle In-Doubt Transactions

Discovering Problems with a Two-Phase Commit

Determining Whether to Perform a Manual Override

Analyzing the Transaction Data

Manually Overriding In-Doubt Transactions

Manually Committing an In-Doubt Transaction

Manually Rolling Back an In-Doubt Transaction

Purging Pending Rows from the Data Dictionary

Executing the PURGE_LOST_DB_ENTRY Procedure

Determining When to Use DBMS_TRANSACTION

Manually Committing an In-Doubt Transaction: Example

Step 1: Record User Feedback

Step 2: Query DBA_2PC_PENDING

Step 3: Query DBA_2PC_NEIGHBORS on Local Node

Step 4: Querying Data Dictionary Views on All Nodes

Step 5: Commit the In-Doubt Transaction

Step 6: Check for Mixed Outcome Using DBA_2PC_PENDING

Simulating Distributed Transaction Failure

Forcing a Distributed Transaction to Fail

Disabling and Enabling RECO

Managing Read Consistency

What is Heterogeneous Services?

Database Links to a Non-Oracle System

Heterogeneous Services Agents

Types of Heterogeneous Services

Transaction Service

SQL Service

Heterogeneous Services Process Architecture

Transparent Gateways

Generic Connectivity

Architecture of the Heterogeneous Services Data Dictionary

Classes and Instances

Data Dictionary Views

Setting Up Access to Non-Oracle Systems

Step 1: Install the Heterogeneous Services Data Dictionary

Step 2: Set Up the Environment to Access Heterogeneous Services Agents

Step 3: Create the Database Link to the Non-Oracle System

Step 4: Test the Connection

Registering Agents

Enabling Agent Self-Registration

Disabling Agent Self-Registration

Using the Heterogeneous Services Data Dictionary Views

Understanding the Types of Views

Understanding the Sources of Data Dictionary Information

Using the General Views

Using the Transaction Service Views

Using the SQL Service Views

Using the Heterogeneous Services Dynamic Performance Views

Determining Which Agents Are Running on a Host

Determining the Open HS Sessions

Determining the HS Parameters

Using the DBMS_HS Package

Specifying Initialization Parameters

Unspecifying Initialization Parameters

What Is Generic Connectivity?

Types of Agents

Generic Connectivity Architecture

SQL Execution

Datatype Mapping

Generic Connectivity Restrictions

Supported Oracle SQL Statements

Functions Supported by Generic Connectivity

Configuring Generic Connectivity Agents

Creating the Initialization File

Editing the Initialization File

Setting Initialization Parameters for an ODBC-based Data Source

Setting Initialization Parameters for an OLE DB-based Data Source

ODBC Connectivity Requirements

OLE DB (SQL) Connectivity Requirements

Data Provider Requirements

OLE DB (FS) Connectivity Requirements

Bookmarks

OLE DB Interfaces

Data Source Properties

Developing Applications with Heterogeneous Services: Overview

Developing Using Pass-Through SQL

Using the DBMS_HS_PASSTHROUGH package

Considering the Implications of Using Pass-Through SQL

Executing Pass-Through SQL Statements

Optimizing Data Transfers Using Bulk Fetch

Using OCI, an Oracle Precompiler, or Another Tool for Array Fetches

Controlling the Array Fetch Between Oracle Database Server and Agent

Controlling the Array Fetch Between Agent and Non-Oracle Server

Controlling the Reblocking of Array Fetches

Researching the Locking Behavior of Non-Oracle Systems

HS_COMMIT_POINT_STRENGTH

HS_DB_DOMAIN

HS_DB_INTERNAL_NAME

HS_DB_NAME

HS_DESCRIBE_CACHE_HWM

HS_FDS_CONNECT_INFO

HS_FDS_SHAREABLE_NAME

HS_FDS_TRACE_LEVEL

HS_FDS_TRACE_FILE_NAME

HS_LANGUAGE

HS_NLS_DATE_FORMAT

HS_NLS_DATE_LANGUAGE

HS_NLS_NCHAR

HS_OPEN_CURSORS

HS_ROWID_CACHE_SIZE

HS_RPC_FETCH_REBLOCKING

HS_RPC_FETCH_SIZE

Data Dictionary Translation Support

Accessing the Non-Oracle Data Dictionary

Supported Views and Tables

Data Dictionary Mapping

Default Column Values

Generic Connectivity Data Dictionary Descriptions

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

DICTIONARY

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

Mapping ODBC Datatypes to Oracle Datatypes

Mapping OLE DB Datatypes to Oracle Datatypes

Contents

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Preface

Part I Distributed Database Systems Concepts and Administration

1 Distributed Database Concepts

2 Managing a Distributed Database

3 Developing Applications for a Distributed Database System

Part II Distributed Transactions Concepts and Administration

4 Distributed Transactions Concepts

5 Managing Distributed Transactions

Part III Heterogeneous Services Concepts and Administration

6 Oracle Heterogeneous Services Concepts

7 Managing Oracle Heterogeneous Services Using Transparent Gateways

8 Managing Heterogeneous Services Using Generic Connectivity

9 Developing Applications with Heterogeneous Services

A Heterogeneous Services Initialization Parameters

B Data Dictionary Views Available Through Heterogeneous Services

C Data Dictionary Translation for Generic Connectivity

D Datatype Mapping

Index