Feature Requests item #921586, was opened at 2004-03-23 08:47 Message generated for change (Settings changed) made by mr-meltdown You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482471&aid=921586&group_id=56967
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Priority: 5 Private: No Submitted By: Stefan Manegold (stmane) Assigned to: Stefan Manegold (stmane) >Summary: M5: calculate selectivity estimates for large tables Initial Comment: [ converted from Bug #894704 originally submitted by Martin Kersten - mlkersten ] The selectivity estimates for tables with >100K elements and a selectivity factor > 20% are severely hampered by the table realloc strategy. Solution. For all (larger) tables take the time to get some basic statistics, e.g. the min/max or possibly a coarse histogram. Use this information to obtain a better estimate of the result size. requires patches to gdk_batop/GDK_select* [source: Cracker experiments] ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=482471&aid=921586&group_id=56967 ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Monetdb-bugs mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/monetdb-bugs
