Comments on: Database problems http://www.rittmanmead.com/2007/01/20/database-problems/ Delivered Intelligence Fri, 30 Jul 2010 17:54:00 -0400 http://wordpress.org/?v=2.8.4 hourly 1 By: Peter Scott http://www.rittmanmead.com/2007/01/20/database-problems/comment-page-1/#comment-4415 Peter Scott Tue, 23 Jan 2007 20:37:45 +0000 http://www.rittmanmead.com/2007/01/20/database-problems/#comment-4415 By taking a set of failing queries we managed to establish that the problem was associated with star transformations that used temporary disk storage (the in-memory ones worked OK). Oracle support are working with us on filing a bug report. The work around of no star transforms caused severe performance problems, and the more acceptable work around of disabling the use of disk based transforms highlighted a parallel query bug, for a small minority of problem queries. We'll get this one cracked... soon??? By taking a set of failing queries we managed to establish that the problem was associated with star transformations that used temporary disk storage (the in-memory ones worked OK). Oracle support are working with us on filing a bug report.

The work around of no star transforms caused severe performance problems, and the more acceptable work around of disabling the use of disk based transforms highlighted a parallel query bug, for a small minority of problem queries.

We’ll get this one cracked… soon???

]]> By: Peter Scott http://www.rittmanmead.com/2007/01/20/database-problems/comment-page-1/#comment-4414 Peter Scott Sun, 21 Jan 2007 08:38:03 +0000 http://www.rittmanmead.com/2007/01/20/database-problems/#comment-4414 For now completely disabled. We are working up a test case that will check whether we can use star transforms without the temporary tables. I have a feeling that we are pushing star transformations a bit too hard - we are using the transformations on <i>snowflake</i> schemas three or four levels deep (don't ask!) For now completely disabled. We are working up a test case that will check whether we can use star transforms without the temporary tables.

I have a feeling that we are pushing star transformations a bit too hard – we are using the transformations on snowflake schemas three or four levels deep (don’t ask!)

]]> By: David Aldridge http://www.rittmanmead.com/2007/01/20/database-problems/comment-page-1/#comment-4413 David Aldridge Sun, 21 Jan 2007 02:37:31 +0000 http://www.rittmanmead.com/2007/01/20/database-problems/#comment-4413 Did you completely disable star transformations Pete, or just the temp table bit? I remember that causing problems before. Did you completely disable star transformations Pete, or just the temp table bit? I remember that causing problems before.

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