Archive for the 'materialized views'

refresh “fast” of materialized views optimized by Oracle as “complete”

In my current “big” project, I am building a network of nested materialized views to transform rows of one schema into rows of another (very different) schema. The former is used by the old (but still live) version of an application of ours, the latter by the new version; our idea is...
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fast refresh of join-only MVs: _mv_refresh_use_stats and locking log stats

A devastating performance degradation of materialized view fast refreshes can happen in versions after 9i – and can be healed rather easily by simply setting the hidden parameter _mv_refresh_use_stats or, a bit surprisingly, by locking statistics on the logs. The problem can manifest at least...
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11gR2: new algorithm for fast refresh of on-commit materialized views

This post investigates the improvements that have been made in 11gR2 to the fast refresh engine of materialized views (MVs) that are set to be automatically refreshed at commit time. We speak about join-only materialized views only in this post, as always with the help of a test case. As noted in...
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11gR2: materialized view logs changes

In this post we are going to discuss some 11gR2 changes to materialized view logs that are aimed at increasing the performance of the fast-refresh engine of materialized views (MVs), especially the on-commit variant. The MV logs, in 10gr2, now comes in two flavours: the traditional (and still...
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fast refresh of single-table materialized views – algorithm summary

Today we are going to investigate how Oracle fast refreshes materialized views (MVs) of a single master table, containing no aggregate but, at most, filter predicates and additional column definitions: create materialized view test_mv build immediate refresh fast on demand with rowid -- with...
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