匿名用户oracle中能查看历史的执行计划,当某个语句原来挺快的,某一天变慢了,可以对比之前的执行计划,
看看计划是否走了不是最优 的,请问db2 中如何查看
select * from table(dbms_xplan.display_awr('&sql_id'));
select to_char(begin_interval_time, 'yyyy-mm-dd hh24:mi:ss') begin_time, a.sql_id, a.plan_hash_value, a.instance_number, module, plan_hash_value, EXECUTIONS_DELTA exec, decode(EXECUTIONS_DELTA, 0, buffer_gets_deltA, round(BUFFER_GETS_DELTA / EXECUTIONS_DELTA)) per_get, decode(EXECUTIONS_DELTA, 0, ROWS_PROCESSED_DELTA, round(ROWS_PROCESSED_DELTA / EXECUTIONS_DELTA, 3)) per_rows, decode(EXECUTIONS_DELTA, 0, ELAPSED_TIME_DELTA, round(ELAPSED_TIME_DELTA / EXECUTIONS_DELTA / 1000, 2)) time_ms, decode(EXECUTIONS_DELTA, 0, DISK_READS_DELTA, round(DISK_READS_DELTA / EXECUTIONS_DELTA, 2)) per_read from dba_hist_sqlstat a, DBA_HIST_SNAPSHOT b where a.snap_id = b.snap_id and a.instance_number = b.instance_number and a.sql_id = '&sql_id' order by 1 desc;
看看这个
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