系统库按时间生成IO TOP SQL语句(08点-11点)

最新推荐文章于 2024-07-31 17:06:19 发布

原创最新推荐文章于 2024-07-31 17:06:19 发布 · 724 阅读

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#sql #io #module #null #disk

本文详细解析了SQL性能分析的关键指标，包括物理读取次数、每执行次数的读取数、总百分比、CPU时间、执行时间及SQL文本等，并通过查询优化提升系统性能。

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select *
from (select sqt.dskr "Physical Reads",
               sqt.exec,
               decode(sqt.exec, 0, to_number(null), (sqt.dskr / sqt.exec)) "Reads per Exec",
               (100 * sqt.dskr) /
               (SELECT sum(e.VALUE) - sum(b.value)
                  FROM DBA_HIST_SYSSTAT b, DBA_HIST_SYSSTAT e
                 WHERE B.SNAP_ID =
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'08')
                   AND E.SNAP_ID =
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'11')
                   AND B.DBID = 911569205
                   AND E.DBID = 911569205
                   AND B.INSTANCE_NUMBER = 1
                   AND E.INSTANCE_NUMBER = 1
                   and e.STAT_NAME = 'physical reads'
                   and b.stat_name = 'physical reads') "%Total",
               nvl((sqt.cput / 1000000), to_number(null)) "CPU Time (s)",
               nvl((sqt.elap / 1000000), to_number(null)) "Elapsed Time (s)",
               sqt.sql_id,
               decode(sqt.module, null, null, 'Module: ' || sqt.module) "SQL Module",
               nvl(st.sql_text, to_clob('** SQL Text Not Available **')) "SQL Text"
          from (select sql_id,
                       max(module) module,
                       sum(disk_reads_delta) dskr,
                       sum(executions_delta) exec,
                       sum(cpu_time_delta) cput,
                       sum(elapsed_time_delta) elap
                  from dba_hist_sqlstat
                 where dbid = 911569205
                   and instance_number = 1
                   and snap_id >
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'08')
                   and snap_id <=
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'11')
                 group by sql_id)sqt,
               dba_hist_sqltext st
         where st.sql_id(+) = sqt.sql_id
           and st.dbid(+) = 911569205
           and (SELECT sum(e.VALUE) - sum(b.value)
                  FROM DBA_HIST_SYSSTAT b, DBA_HIST_SYSSTAT e
                 WHERE B.SNAP_ID =
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'08')
                   AND E.SNAP_ID =
                       (select snap_id
                          from DBA_HIST_SNAPSHOT
                         where to_char(end_interval_time, 'yyyymmddhh24') =to_char(sysdate,'yyyymmdd')||'11')
                   AND B.DBID = 911569205
                   AND E.DBID = 911569205
                   AND B.INSTANCE_NUMBER = 1
                   AND E.INSTANCE_NUMBER = 1
                   and e.STAT_NAME = 'physical reads'
                   and b.stat_name = 'physical reads')>0
         order by nvl(sqt.dskr, -1) desc, sqt.sql_id)
where rownum < 65 and(rownum <= 10 or "%Total" > 1)