原文地址：http://blog.itpub.net/28536251/viewspace-2019984/
SQL执行过程中硬解析占比过高，影响SQL执行效率，其原因有可能是游标缓存不足，通过如下语句查询可以看到使用率已经100%，建议根据实际业务增大游标缓存。
SQL> show parameter session_cached_cursors;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
session_cached_cursors integer 50
SQL> 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');
PARAMETER VALUE USAGE
---------------------- ---------- -----
session_cached_cursors 50 100%
open_cursors 300 20%