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SKEWONLY' WORKS !!!!!!!!

From: Juan Carlos Reyes Pacheco <jreyes_at_dazasoftware.com>
Date: Fri, 13 Aug 2004 11:42:17 -0400
Message-Id: <411CE159.000003.00352@CACHITOSS>


Hi list,
after reading the effect of histogramas, I decided do not gather histograms, without testing before, so I droped and recalculated statistics ( in more than one production database) without getting them with the skew only optoin

I did this
EXEC DBMS_STATS.DELETE_DATABASE_STATS(); EXEC DBMS_STATS.GATHER_database_STATS( );

Then all the useres started to complaint somep rocess were slower, some of them were 100% slower, then I gather againt histogram statistics and all return to normality.
EXEC DBMS_STATS.GATHER_database_STATS( ESTIMATE_PERCENT=>100,METHOD_OPT=> FOR ALL COLUMNS SIZE SKEWONLY'); So based on my experience in 9.2, if you don't use histograms, try to run this command and see if you get some performance (test it )  

Juan Carlos Reyes Pacheco
OCP



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Received on Fri Aug 13 2004 - 10:42:38 CDT

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