EXEC DBMS_STATS.FLUSH_DATABASE_MONITORING_INFO;
SELECT OWNER,TABLE_NAME,OBJECT_TYPE,STALE_STATS,LAST_ANALYZED FROM
DBA_TAB_STATISTICS WHERE (STALE_STATS='YES' OR LAST_ANALYZED IS NULL)
AND OWNER NOT IN ('SYS', 'SYSTEM', 'SYSMAN', 'DMSYS', 'OLAPSYS', 'XDB','EXFSYS', 'CTXSYS',
'WMSYS', 'DBSNMP', 'ORDSYS', 'OUTLN', 'TSMSYS', 'MDSYS') AND TABLE_NAME NOT LIKE 'BIN%';
在进行调优之前,我们就要看表的统计信息是否过期,如果过期了,CBO就可能选择错误的执行计划。
SELECT OWNER,TABLE_NAME,OBJECT_TYPE,STALE_STATS,LAST_ANALYZED FROM DBA_TAB_STATISTICS WHERE WNER='&OWNER' AND TABLE_NAME='&TABLE_NAME';
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