Oracle查看 open_cursors 和 session_cached_cursors

Posted 2021-03-22 Oracle&PostgreSQL

本文转自 http://blog.itpub.net/25583515/viewspace-2152997/

查看当前session已使用的最大open cursor数 和cached cursor数：

SELECT ‘session_cached_cursors‘ PARAMETER,
       LPAD (VALUE, 5) VALUE,
       DECODE (VALUE, 0, ‘ n/a‘, TO_CHAR (100 * USED / VALUE, ‘990‘) || ‘%‘)
          USAGE
  FROM (SELECT MAX (S.VALUE) USED
          FROM V$STATNAME N, V$SESSTAT S
         WHERE     N.NAME = ‘session cursor cache count‘
               AND S.STATISTIC# = N.STATISTIC#),
       (SELECT VALUE
          FROM V$PARAMETER
         WHERE NAME = ‘session_cached_cursors‘)
UNION ALL
SELECT ‘open_cursors‘,
       LPAD (VALUE, 5),
       TO_CHAR (100 * USED / VALUE, ‘990‘) || ‘%‘
  FROM (  SELECT MAX (SUM (S.VALUE)) USED
            FROM V$STATNAME N, V$SESSTAT S
           WHERE     N.NAME IN (‘opened cursors current‘,
                                ‘session cursor cache count‘)
                 AND S.STATISTIC# = N.STATISTIC#
        GROUP BY S.SID),
       (SELECT VALUE
          FROM V$PARAMETER
         WHERE NAME = ‘open_cursors‘);

注：如果查询的session open cursor到达100% client就很可能报错ORA-01000

 查看session open cursor的具体程式、open cursor数量：

 

SELECT a.inst_id,
     a.sid,
     a.USERNAME,
     a.SCHEMANAME,
     a.OSUSER,
     a.machine,
     a.TERMINAL,
     a.LOGON_TIME,
     a.PROGRAM,
     a.STATUS,
     b.name,
     b.used
FROM gv$session a,
     (SELECT n.inst_id,
             sid,
             n.name,
             s.VALUE used
        FROM gv$statname n, gv$sesstat s
       WHERE     n.name IN (‘opened cursors current‘,
                            ‘session cursor cache count‘)
             AND s.statistic# = n.statistic#
             AND n.inst_id = s.inst_id) b
WHERE     a.sid = b.sid
     AND a.inst_id = b.inst_id
     AND b.name <> ‘session cursor cache count‘
ORDER BY b.used DESC;

查看session open cursor的具体SQL(此方法是联合v$open_cursor得出的结果，可能有不准确。但session最多open_cursors的SQL一定是在运行结果中)

SELECT distinct a.inst_id,
         a.sid,
         a.USERNAME,
         a.SCHEMANAME,
         a.OSUSER,
         a.machine,
         a.TERMINAL,
         a.LOGON_TIME,
         a.PROGRAM,
         a.STATUS,
         b.name,
         b.used,c.sql_id
  FROM   gv$session a,
         (SELECT   n.inst_id, sid, n.name, s.VALUE used
            FROM   gv$statname n, gv$sesstat s
           WHERE   n.name IN
                         (‘opened cursors current‘,
                          ‘session cursor cache count‘)
                   AND s.statistic# = n.statistic# and n.inst_id=s.inst_id ) b,v$open_cursor c
 WHERE   a.sid = b.sid and a.inst_id = b.inst_id and a.sid=c.sid and c.CURSOR_TYPE in(‘OPEN‘,‘OPEN-PL/SQL‘,‘OPEN-RECURSIVE‘)
 and b.name <> ‘session cursor cache count‘
 order by b.used desc;