zoukankan      html  css  js  c++  java
  • enq: SQ

    --每分钟操作
    SQL> select  sql_id, mi, count(mi)
      2    from (select event, sql_id, to_char(sample_time, 'yyyymmdd hh24mi') mi --,
      3          --session_id
      4            from dba_hist_active_sess_history
      5           where sql_id = '7wxfw53bsmgpq'
      6             and sample_time > to_date('20140717 0940', 'yyyymmdd hh24mi')
      7             and sample_time < to_date('20140717 0950', 'yyyymmdd hh24mi'))
      8   group by  sql_id, mi
      9    order by mi ;

    SQL_ID        MI             COUNT(MI)
    ------------- ------------- ----------
    7wxfw53bsmgpq 20140717 0942          1
    7wxfw53bsmgpq 20140717 0943         23
    7wxfw53bsmgpq 20140717 0944        125
    7wxfw53bsmgpq 20140717 0946         96
    7wxfw53bsmgpq 20140717 0947        114
    7wxfw53bsmgpq 20140717 0949         44

    通过图片,发现对 第一条获取序列的语句比較暂用性能

    --等待事件以及语句情况
    SQL> select  event,sql_id, mi, count(mi)
      2    from (select substrb(event,1.30) event, sql_id, to_char(sample_time, 'yyyymmdd hh24mi') mi --,
      3          --session_id
      4            from dba_hist_active_sess_history
      5           where sql_id = '7wxfw53bsmgpq'

      6             and sample_time > to_date('20140717 0940', 'yyyymmdd hh24mi')
      7             and sample_time < to_date('20140717 0950', 'yyyymmdd hh24mi'))
      8   group by  event,sql_id, mi
      9    order by mi ;

    EVENT                                                            SQL_ID        MI             COUNT(MI)
    ---------------------------------------------------------------- ------------- ------------- ----------
                                                                     7wxfw53bsmgpq 20140717 0942          1
    buffer busy waits                                                7wxfw53bsmgpq 20140717 0943          1
    enq: SQ - contention                                             7wxfw53bsmgpq 20140717 0943         22
    buffer busy waits                                                7wxfw53bsmgpq 20140717 0944          3

    enq: SQ - contention                                             7wxfw53bsmgpq 20140717 0944        122
    buffer busy waits                                                7wxfw53bsmgpq 20140717 0946          2
    enq: SQ - contention                                             7wxfw53bsmgpq 20140717 0946         94
    buffer busy waits                                                7wxfw53bsmgpq 20140717 0947          2
    enq: SQ - contention                                             7wxfw53bsmgpq 20140717 0947        112
    buffer busy waits                                                7wxfw53bsmgpq 20140717 0949          1
    enq: SQ - contention                                             7wxfw53bsmgpq 20140717 0949         43


    --大小获取查询
    SQL> select sequence_name,cache_size from dba_sequences where sequence_name like upper('%qreque%');

    SEQUENCE_NAME                  CACHE_SIZE
    ------------------------------ ----------
    QREQUESTNO                             20 改成100  在測试

    SQL>

    --大小获取查询
    SQL> select sequence_name,cache_size from dba_sequences where sequence_name like upper('%qreque%');

    SEQUENCE_NAME                  CACHE_SIZE
    ------------------------------ ----------
    QREQUESTNO                             20 变100  在测试

    版权声明:本文博客原创文章。博客,未经同意,不得转载。

  • 相关阅读:
    数据库设计>相片管理设计思路小讨论
    ADO.NET数据库连接的几种方式
    ADO.NET两种事务处理方法
    ADO.NET调用存储过程
    [sql server] 得到连续日期查询(转)
    数据库设计基础>范式
    repeater控件的事件
    小偷程序的学习总结
    《道德经》程序员版第十章
    数据库设计基础>ER图(转)
  • 原文地址:https://www.cnblogs.com/zfyouxi/p/4640703.html
Copyright © 2011-2022 走看看