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Materialized View Refresh : Log Population and Purge (Doc ID 236233.1)

Last updated on FEBRUARY 22, 2019

Applies to:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.

Purpose

The purpose of this article is to explain Oracle's materialized view fast
refresh mechanism. It also discusses the performance, problems related to
materialized view log management.

NB: The terms Snapshot and Materialized View are synonymous.

Scope

This is for customers of all levels of expertise in dealing with materialized views.

Details

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In this Document
Purpose
Scope
Details
 1. FAST REFRESH
 1.1 DATABASE OBJECTS INVOLVED IN THE FAST REFRESH MECHANISM
 1.1.1 What does an MView consists of
 1.1.2 What does an MView log on a master table consists of
 1.1.3 An AFTER ROW trigger on the master table named TLOG$_<table_name>
 1.2 REGISTRATION
 1.3 FAST REFRESH OPERATION
 2. MVIEW LOG MANAGEMENT
 2.1 WHEN MVIEW LOG ENTRIES CAN BE PURGED?
 2.1.1. HOW FAST REFRESH IS PERFORMED AND WHEN THE MVIEW LOG GETS PURGED
 2.1.2 COMPLETE REFRESH
 2.1.3 PURGE PROBLEMS
 2.2 MANAGING MVIEW LOG SPACE
 2.2.1 TRUNCATING A MVIEW LOG
 2.2.2 REORGANIZING MASTER TABLES THAT HAVE MVIEW LOGS
 3. RELATED BUGS
References

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