{"id":712,"date":"2012-04-03T23:36:15","date_gmt":"2012-04-03T15:36:15","guid":{"rendered":"https:\/\/yangtingkun.net\/?p=712"},"modified":"2012-04-05T12:37:04","modified_gmt":"2012-04-05T04:37:04","slug":"%e5%ae%a2%e6%88%b7%e6%95%b0%e6%8d%ae%e5%ba%93%e5%87%ba%e7%8e%b0%e5%a4%a7%e9%87%8fcache-buffer-chains-latch","status":"publish","type":"post","link":"https:\/\/yangtingkun.net\/?p=712","title":{"rendered":"\u5ba2\u6237\u6570\u636e\u5e93\u51fa\u73b0\u5927\u91cfcache buffer chains latch"},"content":{"rendered":"

\u5ba2\u6237\u4ea7\u54c1\u6570\u636e\u5e93\u4e0a\u5348\u51fa\u73b0\u4e86\u4e25\u91cd\u7684\u6027\u80fd\u95ee\u9898\uff0c\u7b80\u5355\u8bb0\u5f55\u4e00\u4e0b\u95ee\u9898\u7684\u8bca\u65ad\u548c\u89e3\u51b3\u8fc7\u7a0b\u3002<\/p>\n

\u53ef\u4ee5\u770b\u5230\uff0c\u6570\u636e\u5e93\u7684DB TIME\u5df2\u7ecf\u6da8\u5230\u4e86\u975e\u5e38\u9ad8\u7684\u5730\u6b65\uff0c\u8fd9\u8bf4\u660e\u7cfb\u7edf\u6b63\u7ecf\u53d7\u7740\u975e\u5e38\u4e25\u91cd\u7684\u6027\u80fd\u95ee\u9898\uff1a<\/p>\n

\n\n\n\n\n\n\n\n
<\/td>\n\n

Snap Id<\/strong><\/p>\n<\/td>\n

\n

Snap Time<\/strong><\/p>\n<\/td>\n

\n

Sessions<\/strong><\/p>\n<\/td>\n

\n

Cursors\/Session<\/strong><\/p>\n<\/td>\n<\/tr>\n

\n

Begin Snap:<\/p>\n<\/td>\n

\n

7170<\/p>\n<\/td>\n

\n

31-3\u6708 -12 08:00:50<\/p>\n<\/td>\n

\n

395<\/p>\n<\/td>\n

\n

10.5<\/p>\n<\/td>\n<\/tr>\n

\n

End Snap:<\/p>\n<\/td>\n

\n

7172<\/p>\n<\/td>\n

\n

31-3\u6708 -12 09:00:27<\/p>\n<\/td>\n

\n

689<\/p>\n<\/td>\n

\n

11.7<\/p>\n<\/td>\n<\/tr>\n

\n

Elapsed:<\/p>\n<\/td>\n

<\/td>\n\n

59.61 (mins)<\/p>\n<\/td>\n

<\/td>\n<\/td>\n<\/tr>\n
\n

DB Time:<\/p>\n<\/td>\n

<\/td>\n\n

17,270.93 (mins)<\/p>\n<\/td>\n

<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\u4eceTOP 5\u770b\uff0c\u7b49\u5f85\u4e8b\u4ef6\u4e2d\u6700\u660e\u663e\u7684\u662flatch: cache buffers chains\uff0c\u4ece\u5f53\u524d\u7cfb\u7edf\u7684\u72b6\u6001\u4e5f\u53ef\u4ee5\u770b\u5230\u8fd9\u4e00\u70b9\uff1a<\/p>\n

SQL> SELECT EVENT, COUNT(*) FROM GV$SESSION GROUP BY EVENT HAVING COUNT(*) > 5 ORDER BY 2 DESC;\r\n\r\nEVENT\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 COUNT(*)\r\n---------------------------------------------------------------- ----------\r\nlatch: cache buffers chains\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1043\r\nSQL*Net message from client\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 500\r\nSQL*Net message to client\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 35\r\nrdbms ipc message\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 29\r\ngc cr request\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a025\r\nlatch free\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 13\r\ngcs remote message\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 10\r\ngc buffer busy\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 7\r\n\r\n8 rows selected.<\/pre>\n
\u7cfb\u7edf\u4e2d\u90e8\u5206SQL\u7684\u6267\u884c\u65f6\u95f4\u5df2\u7ecf\u957f\u8fbe\u51e0\u4e2a\u5c0f\u65f6\uff1a<\/p>\n
SQL ordered by Elapsed Time<\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n
Elapsed Time (s)<\/strong><\/p>\n<\/td>\n
\n
CPU Time (s)<\/strong><\/p>\n<\/td>\n
\n
Executions <\/strong><\/p>\n<\/td>\n
\n
Elap per Exec \u00a0 (s) <\/strong><\/p>\n<\/td>\n
\n
% Total DB Time<\/strong><\/p>\n<\/td>\n
\n
SQL Id<\/strong><\/p>\n<\/td>\n
\n
SQL Module<\/strong><\/p>\n<\/td>\n
\n
SQL Text<\/strong><\/p>\n<\/td>\n<\/tr>\n
\n
341,821<\/p>\n<\/td>\n
\n
11,917<\/p>\n<\/td>\n
\n
112<\/p>\n<\/td>\n
\n
3051.97<\/p>\n<\/td>\n
\n
32.99<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
244,752<\/p>\n<\/td>\n
\n
3,380<\/p>\n<\/td>\n
\n
147<\/p>\n<\/td>\n
\n
1664.98<\/p>\n<\/td>\n
\n
23.62<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
52,419<\/p>\n<\/td>\n
\n
11,331<\/p>\n<\/td>\n
\n
3<\/p>\n<\/td>\n
\n
17472.91<\/p>\n<\/td>\n
\n
5.06<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
select \u00a0 cf.cardid, (CASE WHEN c…<\/p>\n<\/td>\n<\/tr>\n
\n
38,767<\/p>\n<\/td>\n
\n
532<\/p>\n<\/td>\n
\n
11<\/p>\n<\/td>\n
\n
3524.24<\/p>\n<\/td>\n
\n
3.74<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
37,146<\/p>\n<\/td>\n
\n
2,524<\/p>\n<\/td>\n
\n
2<\/p>\n<\/td>\n
\n
18573.15<\/p>\n<\/td>\n
\n
3.58<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
30,796<\/p>\n<\/td>\n
\n
2,331<\/p>\n<\/td>\n
\n
5<\/p>\n<\/td>\n
\n
6159.20<\/p>\n<\/td>\n
\n
2.97<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
29,991<\/p>\n<\/td>\n
\n
2,506<\/p>\n<\/td>\n
\n
1<\/p>\n<\/td>\n
\n
29991.41<\/p>\n<\/td>\n
\n
2.89<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM ( s…<\/p>\n<\/td>\n<\/tr>\n
\n
24,762<\/p>\n<\/td>\n
\n
875<\/p>\n<\/td>\n
\n
3<\/p>\n<\/td>\n
\n
8254.06<\/p>\n<\/td>\n
\n
2.39<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM (SE…<\/p>\n<\/td>\n<\/tr>\n
\n
17,845<\/p>\n<\/td>\n
\n
699<\/p>\n<\/td>\n
\n
2<\/p>\n<\/td>\n
\n
8922.50<\/p>\n<\/td>\n
\n
1.72<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
SELECT count(*) \u00a0 total FROM (SE…<\/p>\n<\/td>\n<\/tr>\n
\n
17,470<\/p>\n<\/td>\n
\n
1,295<\/p>\n<\/td>\n
\n
0<\/p>\n<\/td>\n
<\/td>\n\n
1.69<\/p>\n<\/td>\n
\n
\n<\/td>\n
\n
JDBC Thin Client<\/p>\n<\/td>\n
\n
select * from \u00a0 (select aa.*, ro…<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
 <\/p>\n
 <\/p>\n
\u5176\u5b9e\u6839\u636e\u8fd9\u4e9b\u73b0\u8c61\uff0c\u57fa\u672c\u4e0a\u53ef\u4ee5\u5224\u65ad\u95ee\u9898\u4e86\u3002\u80af\u5b9a\u662fSQL\u6267\u884c\u8ba1\u5212\u7684\u6539\u53d8\u5bfc\u81f4\u4e86\u5f53\u524d\u7684\u6027\u80fd\u95ee\u9898\u3002\u800c\u7c7b\u4f3c\u7ed1\u5b9a\u53d8\u91cf\u7aa5\u63a2\u4e4b\u7c7b\u7684\u95ee\u9898\u53ea\u4f1a\u5f71\u54cd\u4e2a\u522b\u7684SQL\uff0c\u800c\u8fd9\u4e48\u5927\u9762\u79ef\u7684\u6267\u884c\u8ba1\u5212\u7684\u6539\u53d8\uff0c\u51e0\u4e4e\u53ef\u4ee5\u65ad\u5b9a\u662f\u7edf\u8ba1\u4fe1\u606f\u9020\u6210\u7684\u3002<\/p>\n
\u8be2\u95ee\u4e86\u4e00\u4e0b\u5ba2\u6237\u6700\u8fd1\u7684\u64cd\u4f5c\uff0c\u539f\u6765\u6628\u5929\u591c\u91cc\u901a\u8fc7\u6570\u636e\u5e93\u94fe\u7684\u65b9\u5f0f\u5bfc\u5165\u4e86\u4e00\u90e8\u5206\u6570\u636e\u3002\u800c\u4eca\u5929\u4e00\u65e9\u95ee\u9898\u5c31\u51fa\u73b0\u4e86\u3002<\/p>\n
\u5176\u5b9e\u95ee\u9898\u5df2\u7ecf\u5f88\u660e\u663e\u4e86\uff0c\u5728\u901a\u8fc7\u6570\u636e\u5e93\u94fe\u52a0\u8f7d\u6570\u636e\u540e\uff0c\u5e76\u6ca1\u6709\u91cd\u65b0\u6536\u96c6\u7edf\u8ba1\u4fe1\u606f\uff0c\u4e14\u7531\u4e8e\u52a0\u8f7d\u65f6\u95f4\u662f\u5728\u534a\u591c\uff0c\u8fd9\u6279\u6570\u636e\u4e5f\u6ca1\u6709\u8d76\u4e0a\u6bcf\u592922:00\u7684\u7edf\u8ba1\u4fe1\u606f\u81ea\u52a8\u6536\u96c6\u7684\u5de5\u4f5c\u3002\u8fd9\u5c31\u4f7f\u5f97Oracle\u5728\u751f\u6210\u6267\u884c\u8ba1\u5212\u65f6\uff0c\u4f1a\u4f9d\u8d56\u6570\u636e\u52a0\u8f7d\u524d\u7684\u7edf\u8ba1\u4fe1\u606f\uff0c\u4ece\u800c\u9020\u6210\u4e86\u9519\u8bef\u7684\u6267\u884c\u8ba1\u5212\u3002<\/p>\n
\u9996\u5148\u89e3\u51b3\u95ee\u9898\u7684\u6839\u6e90\u95ee\u9898\uff0c\u5bf9\u52a0\u8f7d\u8fc7\u6570\u636e\u7684\u8868\u91cd\u65b0\u6536\u96c6\u7edf\u8ba1\uff1a<\/p>\n
SQL> SELECT 'EXEC DBMS_STATS.GATHER_TABLE_STATS(''USER1'', ''' || TABLE_NAME || ''', CASCADE => TRUE)' FROM DBA_TABLES WHERE OWNER = 'USER1' AND LAST_ANALYZED > TRUNC(SYSDATE);\r\n\r\n'EXECDBMS_STATS.GATHER_TABLE_STATS(''USER1'','''||TABLE_NAME||''',CASCADE=>TRUE)'\r\n-----------------------------------------------------------------------------------------\r\nEXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', 'TABLE_1', CASCADE => TRUE)\r\nEXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', 'TABLE_2', CASCADE => TRUE)\r\n.\r\n.\r\n.\r\nEXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', 'TABLE_3', CASCADE => TRUE)\r\nEXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', 'TABLE_4', CASCADE => TRUE)\r\n\r\n12 rows selected.\r\n\r\nSQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', ' TABLE_1', CASCADE => TRUE)\r\n\r\nPL\/SQL procedure successfully completed.\r\n\r\nSQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', ' TABLE_2', CASCADE => TRUE)\r\n\r\nPL\/SQL procedure successfully completed.\r\n\r\n.\r\n.\r\n.\r\n\r\nSQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', ' TABLE_3', CASCADE => TRUE)\r\n\r\nPL\/SQL procedure successfully completed.\r\n\r\nSQL> EXEC DBMS_STATS.GATHER_TABLE_STATS('USER1', ' TABLE_4', CASCADE => TRUE)\r\n\r\nPL\/SQL procedure successfully completed.<\/pre>\n
\u867d\u7136\u95ee\u9898\u7684\u6839\u6e90\u5df2\u7ecf\u88ab\u89e3\u51b3\uff0c\u4f46\u662f\u5f53\u524d\u8fd0\u884c\u7684SQL\u5e76\u4e0d\u4f1a\u6539\u53d8\u6267\u884c\u8ba1\u5212\uff0c\u56e0\u6b64\u8fd8\u9700\u8981\u627e\u5230\u95ee\u9898\u7684SQL\uff0c\u4ece\u540e\u53f0\u5c06\u5176\u7ed3\u675f\uff1a<\/p>\n
SQL> SELECT 'kill -9 ' || spid from v$session s, v$process p where s.username = 'USER2' and s.paddr = p.addr and event = 'latch: cache buffers chains';\r\n\r\n'KILL-9'||SPID\r\n--------------------\r\nkill -9 28321\r\nkill -9 25384\r\nkill -9 23697\r\nkill -9 7239\r\n.\r\n.\r\n.\r\nkill -9 9331\r\nkill -9 13759\r\n\r\n740 rows selected.\r\n\r\nSQL> SELECT 'kill -9 ' || spid from gv$session s, gv$process p where s.username = 'USER2' and s.paddr = p.addr and event = 'latch: cache buffers chains' and s.inst_id = p.inst_id and s.inst_id = 2;\r\n\r\n'KILL-9'||SPID\r\n--------------------\r\nkill -9 23992\r\nkill -9 5289\r\nkill -9 21067\r\nkill -9 16816\r\nkill -9 16820\r\nkill -9 26767\r\n.\r\n.\r\n.\r\nkill -9 14981\r\nkill -9 26678\r\nkill -9 26682\r\n\r\n258 rows selected.<\/pre>\n
\u5206\u522b\u5728\u4e24\u4e2a\u8282\u70b9\u6740\u6389\u8fd9\u4e9b\u6267\u884c\u8ba1\u5212\u5b58\u5728\u95ee\u9898\u7684\u4f1a\u8bdd\uff0c\u91ca\u653e\u88ab\u5927\u91cf\u5360\u7528\u7684\u7cfb\u7edf\u8d44\u6e90\u3002<\/p>\n
\u7531\u4e8eOracle\u7684\u6267\u884c\u8ba1\u5212\u5e76\u975e\u5728\u6536\u96c6\u7edf\u8ba1\u4fe1\u606f\u540e\u9a6c\u4e0a\u751f\u6548\uff0c\u56e0\u6b64\u8fd8\u6709\u4e2a\u522b\u7684SQL\u4ecd\u7136\u6cbf\u7528\u9519\u8bef\u7684\u6267\u884c\u8ba1\u5212\uff1a<\/p>\n
SQL> select distinct inst_id, sql_id from gv$session where event = 'latch: cache buffers chains';\r\n\r\nINST_ID SQL_ID\r\n---------- -------------\r\n1 39gvg7vbcm8jx\r\n1 a6aqkm30u7p90\r\n\r\nSQL> select address, hash_value from v$sqlarea where sql_id = 'a6aqkm30u7p90'\uff1b\r\n\r\nADDRESS HASH_VALUE\r\n---------------- ----------\r\nC000000EB7ED3420 3248739616\r\n\r\nSQL> exec dbms_shared_pool.purge('C000000EB7ED3420,3248739616','C')\r\n\r\nPL\/SQL procedure successfully completed.\r\n\r\nSQL> select address, hash_value from v$sqlarea where sql_id ='39gvg7vbcm8jx';\r\n\r\nADDRESS HASH_VALUE\r\n---------------- ----------\r\nC000001037B8E308 3603538493\r\n\r\nSQL> exec dbms_shared_pool.purge('C000001037B8E308\u2019, \u20183603538493', 'C')\r\n\r\nPL\/SQL procedure successfully completed.<\/pre>\n
\u7531\u4e8e\u5f53\u524d\u7684\u6570\u636e\u5e93\u7248\u672c\u662f10.2.0.5\uff0c\u56e0\u6b64\u53ef\u4ee5\u5f88\u65b9\u4fbf\u7684\u4f7f\u7528dbms_shared_pool\u5c06\u6267\u884c\u8ba1\u5212\u9519\u8bef\u7684SQL\u6e05\u9664\u51fa\u5171\u4eab\u6c60\uff0c\u5f3a\u5236\u5176\u91cd\u65b0\u751f\u6210\u6267\u884c\u8ba1\u5212\u3002<\/p>\n
SQL> select event, count(*) from gv$session where username like != user GROUP BY EVENT order by 2 desc;\r\n\r\nEVENT \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0COUNT(*)\r\n---------------------------------------------------------------- ----------\r\nSQL*Net message from client \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0370\r\nSQL*Net message to client \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a015\r\ngc cr request \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010\r\nlatch free \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\r\nStreams AQ: waiting for messages in the queue \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\r\n\r\n5 rows selected.<\/pre>\n
\u6570\u636e\u5e93\u4e2dSQL\u6267\u884c\u8ba1\u5212\u9519\u8bef\u9664\u4e86\u5bfc\u81f4\u5927\u91cf\u7684latch: cache buffers chains\u7b49\u5f85\u4ee5\u5916\uff0c\u8fd8\u5b58\u5728gc cr request\u548clatch free\u7b49\u8fd9\u4e9b\u7b49\u5f85\u4e8b\u4ef6\uff0c\u7ecf\u5206\u6790\u540c\u6837\u662f\u7531\u4e8e\u9519\u8bef\u7684\u6267\u884c\u8ba1\u5212\u6240\u81f4\u3002\u5c06\u8fd9\u4e9b\u4f1a\u8bdd\u91c7\u7528\u76f8\u540c\u7684\u65b9\u6cd5\u6e05\u9664\u540e\uff0c\u7cfb\u7edf\u8d1f\u8f7d\u6062\u590d\u5230\u6b63\u5e38\u8303\u56f4\uff1a<\/p>\n
\n\n\n\n\n\n\n\n
<\/td>\n\n
Snap Id<\/strong><\/p>\n<\/td>\n
\n
Snap Time<\/strong><\/p>\n<\/td>\n
\n
Sessions<\/strong><\/p>\n<\/td>\n
\n
Cursors\/Session<\/strong><\/p>\n<\/td>\n<\/tr>\n
\n
Begin Snap:<\/p>\n<\/td>\n
\n
7188<\/p>\n<\/td>\n
\n
31-3\u6708 -12 14:55:17<\/p>\n<\/td>\n
\n
257<\/p>\n<\/td>\n
\n
20.3<\/p>\n<\/td>\n<\/tr>\n
\n
End Snap:<\/p>\n<\/td>\n
\n
7189<\/p>\n<\/td>\n
\n
31-3\u6708 -12 15:03:07<\/p>\n<\/td>\n
\n
256<\/p>\n<\/td>\n
\n
19.9<\/p>\n<\/td>\n<\/tr>\n
\n
Elapsed:<\/p>\n<\/td>\n
<\/td>\n\n
7.84 (mins)<\/p>\n<\/td>\n
<\/td>\n<\/td>\n<\/tr>\n
\n
DB Time:<\/p>\n<\/td>\n
<\/td>\n\n
70.46 (mins)<\/p>\n<\/td>\n
<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
 <\/p>\n","protected":false},"excerpt":{"rendered":"
\u5ba2\u6237\u4ea7\u54c1\u6570\u636e\u5e93\u4e0a\u5348\u51fa\u73b0\u4e86\u4e25\u91cd\u7684\u6027\u80fd\u95ee\u9898\uff0c\u7b80\u5355\u8bb0\u5f55\u4e00\u4e0b\u95ee\u9898\u7684\u8bca\u65ad\u548c\u89e3\u51b3\u8fc7\u7a0b\u3002 \u53ef\u4ee5\u770b\u5230\uff0c\u6570\u636e\u5e93\u7684DB TIME\u5df2\u7ecf\u6da8\u5230\u4e86\u975e\u5e38\u9ad8\u7684\u5730\u6b65\uff0c\u8fd9\u8bf4\u660e\u7cfb\u7edf\u6b63\u7ecf\u53d7\u7740\u975e\u5e38\u4e25\u91cd\u7684\u6027\u80fd\u95ee\u9898\uff1a Snap Id Snap Time Sessions Cursors\/Session Begin Snap: 7170 31-3\u6708 -12 08:00:50 395 10.5 End Snap: 7172 31-3\u6708 -12 09:00:27 689 11.7 Elapsed: 59.61 (mins) DB Time: 17,270.93 (mins)   \u4eceTOP 5\u770b\uff0c\u7b49\u5f85\u4e8b\u4ef6\u4e2d\u6700\u660e\u663e\u7684\u662flatch: cache buffers chains\uff0c\u4ece\u5f53\u524d\u7cfb\u7edf\u7684\u72b6\u6001\u4e5f\u53ef\u4ee5\u770b\u5230\u8fd9\u4e00\u70b9\uff1a SQL> SELECT … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3],"tags":[588,255,594,484],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2yiY3-bu","_links":{"self":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/712"}],"collection":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=712"}],"version-history":[{"count":1,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/712\/revisions"}],"predecessor-version":[{"id":714,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=\/wp\/v2\/posts\/712\/revisions\/714"}],"wp:attachment":[{"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=712"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=712"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yangtingkun.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=712"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}