Tag Archives: optimizer

Useful stuff from event 10053 traces – part 1

Posted on April 14, 2014 by Marcel-Jan Krijgsman

In theory you can use event 10053 traces to see what choices the optimizer has made, which is very interesting if your query didn’t perform as it was supposed to do. In practice event 10053 traces contain an overwhelming amount … Continue reading →

Posted in Oracle performance tuning | Tagged Beyond Compare, dynamic sampling, event 10053, optimizer, Oracle performance, Oracle SQL tuning, statistics, trace, vimdiff | Leave a comment

More statistics history

Posted on February 19, 2013 by Marcel-Jan Krijgsman

After writing about table statistics, I tried my query to retrieve them many times. Soon I found out, I couldn’t find index statistics data. After a while I figured it out. Duh! The table is called WRI$_OPTSTAT_TAB_HISTORY. So I quickly … Continue reading →

Posted in Oracle performance tuning, Oracle scripts | Tagged column statistics history, histograms, index statistics history, optimizer, Oracle performance, statistics | Leave a comment