Hello Daniel, In the past we observed the situation, that the optimizer statistics have not been calculated optimally for large tabels, if the statistics were calculated based on a sampling of 20.000 rows. This can lead to the situation that the SQL optimizer does not choose the optimal execution plan, which may result in a longer execution time. For bigger tables (>1.000.000 records) it make sense to set the sample rate to 10% instead of 20.000 rows. After executing the command
ALTER TABLE SMM 10 PERCENT the message in the database analyzer should disappear. Best regards, Tilo Heinrich Senior Developer MaxDB&liveCache SAP AG http://www.sap.com <http://www.sap.com/> Sitz der Gesellschaft/Registered Office: Walldorf, Germany Vorstand/SAP Executive Board: Henning Kagermann (Sprecher/CEO), Shai Agassi, Léo Apotheker, Werner Brandt, Claus Heinrich, Gerhard Oswald, Peter Zencke Vorsitzender des Aufsichtsrats/Chairperson of the SAP Supervisory Board: Hasso Plattner Registergericht/Commercial Register Mannheim No HRB 350269 Diese E-Mail kann Betriebs- oder Geschäftsgeheimnisse oder sonstige vertrauliche Informationen enthalten. Sollten Sie diese E-Mail irrtümlich erhalten haben, ist Ihnen eine Kenntnisnahme des Inhalts, eine Vervielfältigung oder Weitergabe der E-Mail ausdrücklich untersagt. Bitte benachrichtigen Sie uns und vernichten Sie die empfangene E-Mail. Vielen Dank. This e-mail may contain trade secrets or privileged, undisclosed, or otherwise confidential information. If you have received this e-mail in error, you are hereby notified that any review, copying, or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal. Thank you for your cooperation. -----Original Message----- From: Daniel Castro Sent: Mittwoch, 13. Juni 2007 20:50 To: maxdb@lists.mysql.com Subject: Statistics Hi, A get the following message in DBA Analyzer: sapdb 1 tables contain > 1.000.000 records but only 20.000 rows will be sampled The table name is SMM. What shall I do? Can you help me? BEst Regards, -- Daniel Castro - דניאל MSN: Skype: danielti2005 ICQ : 316727989 Jabber: danielti Linux User: 387864 AOL User: Danielti2005 Sola Scriptura, Sola Gratia, Sola Fide, Solus Christus, Soli Deo Gloria
