Oracle 11g Streams Implementer's Guide电子书

Oracle 11g Streams Implementer's Guide

Table of Contents

Oracle 11g Streams Implementer's Guide

Credits

About the Authors

About the Reviewers

Preface

Replication in general

Distributed database systems

What is Data Replication?

How do "Replication" and "Distributed Systems" interact?

Why would we want to replicate?

Replication architecture

Replication methods

Replication configurations

Oracle Streams

What this book is (and is NOT)

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. All the Pieces: The Parts of an Oracle 11g Streams Environment

Streams architecture overview

Topology configurations

Single source

Single database

Uni-directional

Cascaded/directed network

Hub-and-Spoke

Multiple source

Bi-directional/N-way/Master-to-Master

Uni-directional Spokes-to-Hub

Bi-directional Spoke-to-Hub

Hybrid

Heterogeneous

Simultaneous versus Synchronous replication

Oracle's Streams replication process flow

Streams components

About those Queues

Capture process—what are we supposed to stream?

Downstream Capture

Synchronous Capture

Instantiation

What sets the instantiation SCN and when?

Propagate process

The Network: COMLINK

Propagation success/failure

Propagation Stream Split and Merge

Apply process

Trigger firing and Apply

Combined Capture and Apply

SCN Coordination—keeps it flowing smoothly

The SCNs of Capture

FIRST_SCN

START_SCN

REQUIRED_CHECKPOINT_SCN

CAPTURED_SCN

APPLIED_SCN

MAXIMUM_SCN

LAST_ENQUEUED_SCN

SOURCE_RESETLOGS_SCN

MAX_CHECKPOINT_SCN

The SCNs of Propagation

The SCNs of Apply

IGNORE_SCN

MAXIMUM_SCN

OLDEST_SCN_NUM

Low-watermark SCN

SCN SYNC-hronization

Capture checkpointing

Archive Log availability

LCRs—what they are and how they work

Extracting data from an LCR

Conflict detection and the LCR

Controlling conflict detection

Types of LCRs and how they get created

Oracle 11g memory and storage architecture (basic) relating to Streams

A word on performance

Streams Change tables

Oracle GoldenGate XSTREAMS

Summary

2. Plot Your Course: Design Considerations

Why?

What?

Where?

Who and How?

When and How?

Other factors to consider

Network capabilities

Transaction sizes

Potential queue growth

Additional hardware resource requirements

Administration and maintenance costs

Third party application requirements

Security

Change auditing

Platform and version compatibility

KISS

Design aid: Streams site matrix

The Matrix template

Summary

3. Prepare the Rafts and Secure Your Gear: The pre-work before configuring Oracle 11g Streams

Network connectivity

Check the waterways

Configure the Oracle Net "Current"

Configure the database

Initialization parameters

Logging features

Archive logging

Supplemental logging

Forced logging

Separate tablespaces

LogMiner tablespace

Streams Administration tablespace

Streams users and privileges

Trusted Streams Administrator user configuration

Untrusted Streams capture, propagation, and apply user configuration

Streams Administration user

Capture user

Propagation user

Apply user

Database links

Trusted versus untrusted configurations

Understanding your Instantiation tools

Using Data Pump to Instantiate

Setting Instantiation SCN manually

Oracle Demo Schemas

Summary

4. Single-Source Configuration

The stream flows one way: Downhill

The Enterprise Manager

Setup options

Configure replication

Processes

Directory objects

Options

Object selection

Review

Schedule Streams setup job

Verify

The code behind the curtain

Checking the waters

Diving in

The proof is in the pudding (or propagation in this case)

Sequences and triggers and Apply

Other levels at which to replicate

The beauty of DBMS_STREAMS_ADM.MAINTAIN_*

Summary

5. N-Way Replication

Pre-planning for N-way replication

Avoiding conflict

The setup

Preliminary setup

Streaming STRM1 to STRM2

Streaming STRM2 to STRM1

Conflict resolution

Extending the example

Rinse and repeat

Summary

6. Get Fancy with Streams Advanced Configurations

Synchronous Capture—straight to the Queue

Subsetting — the micro side of replication

Tag! — you're it

The default behaviour of tags

Making tags work for you

Setting the tag value

Evaluating tags at the replication process rule level

INCLUDE_TAGGED_LCR

INCLUSION_RULE

AND_CONDITION

LCR subprograms

Tag usage

Capture at the Hub

Capture, Propagate, and Apply at each spoke

Apply at the Hub

Propagation at the Hub

RULES — they're what we live by

Rule components

Rule conditions

Rule evaluation context

Action context

Creating your own rules

Rule creation

Rule Sets

Event context

How it all comes together

Rule based transformation — eat your heart out transformers!

Declarative versus User Created

Declarative transformation

User created Rule Based Transformations (UCRBT)

Transformation order of execution

How the transformation is processed

At the Capture (basic and synchronous)

At the Propagation

At the Apply

Transformation errors

At the Capture (basic and synchronous)

At the Propagation

At the Apply

Things to remember when working with Rules

Downstream Capture — avoid white water at the source

Setting up the redo log transport

Configuring the Streams part of DSC

Streams change tables — just tracking the "Facts" Ma'am

Automatic propagation split and merge — redirecting the current

Basic Heterogeneous Configuration

Configuring a Heterogeneous Apply process

Data Transfer via Queue Messaging

Basic XSTREAMS Configuration

XSTREAMS Servers

Configuring the Database

Configuring XSTREAMS Out

Steps for configuring an XSTREAMS Outbound Server

Subsetting Rules for an Outbound Server

Configuring XSTREAMS In

Steps for configuring an XSTREAMS inbound server

Summary

7. Document What You Have and How It Is Working

Mapping the Stream

The Stream without a map

DBMS_STREAMS_ADVISOR_ADM

Making the map

Basic Streams views

UTL_SPADV

Automating the collection of Streams performance data

Summary

8. Dealing with the Ever Constant Tides of Change

Affecting expected change effectively

Changing States: Starting and stopping processes

Database changes

Structure changes to existing objects

Data changes — beware the bulk load!

Expanding your Streamed environment

Example: Adding a Master Site

Time based values used for comparision and time zones.

Example: Adding a table to a replicated schema

Shrinking the Streamed environment

Removing table, scheme, and tablespace level replication from Streams

Removing a site from a Streamed environment

Troubleshooting unexpected changes and resulting Streams errors

Failure Points and Most Likely Causes (a.k.a. FPs and MLCs)

Failure Point 1: DML/DDL statement commit logging

Successful commit

NOLOGGING option

Archive Log mode

Failure Point 2: LogMiner

Supplemental logging

_LOG_PARALLELISM

LOGMNR_MAX_PERSISTENT_SESSIONS

Failure Point 3: Capture process and rules

Memory allocation

Capture process status

Capture queue designation

Capture Rules and Rule Sets

Failure Point 4: Capture enqueue

Capture user privileges

Failure Point 5: Propagation dequeue from Capture queue

Propagation Status

Propagation source configuration

Propagation Job

Failure Point 6: Propagation Rules

Failure Point 7: Database link configuration

Failure Point 8: Network connectivity and stability

Failure Point 9: Propagation enqueue to the Apply queue

Destination availability

Propagation destination configuration

Failure Point 10: Apply dequeue

Apply process status

Apply user privileges

Failure Point 11: Apply Rules

Apply latency

Failure Point 12: Conflict detection and resolution rules

Failure Point 13: Apply Errors

Troubleshooting tools

Enterprise Manager: Streams management

Streams Overview

Command line packages and scripts

Compare and Converge divergent data.

Comparing data

Oracle HealthCheck

Custom QuickCheck

Extract LCRs.

Tricks and tips

Keep propagation going on an unstable network

How to change a Streams process Rule

Summary

9. Appendix and Glossary

Oracle Streams Commander

Streams and Oracle RAC

Oracle GoldenGate

Glossary

Summary

Index