Tag Archives: Oracle performance

Dynamic sampling NOT used for this statement?

So I’m still working on this data warehousing project and performance is not quite optimal. There are all kinds of things to be investigated. One thing I want to find, is the reason why a lot of execution plans show … Continue reading

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Real World Performance Tour

Today I was in Breda, the Netherlands for the Real World Performance Tour, organized bij the Oracle Benelux Users Group. It is a day-long session by Andrew Holdsworth (Senior Director of Oracle’s Real World Performance team), Tom Kyte (who doesn’t … Continue reading

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A walkthrough through sqlperf 1.6 output (video)

I’ve made a video to walk you through the output of the sqlperf script version 1.6.

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sqlperf.sql version 1.6 is out

The main inspiration for this new version of sqlperf.sql is the datawarehouse project I’m currently in. They have performance problems and parallellism seems to be one of the issues. So I needed to know over how many sessions parallellism had … Continue reading

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sql_sql_id_html.sql is now called sqlperf.sql (and new versions too)

[Update]: there is now a non-Diagnostics Pack version here. [Update]:┬áversion 1.6 is now out. More on this blogpost. My collegues are frequently using my SQL performance scripts, but there were some complaints that the scriptnames were a bit too long. … Continue reading

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Expensive full table scans on AQ$_SYS$SERVICE_METRICS_TAB_L

A while ago a collegue DBA asked me to help him with a database he had problems with. The database was generating a lot of archives and since there also was a standby database, these archives had to be transported … Continue reading

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Mining the log writer trace

A while ago I wrote about rediculous log writer waits I have encountered. It turned out to have to do something with caching issues in our storage virtualization implementation. Unfortunately I don’t know the exact details. Storage has still secrets … Continue reading

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