http://t.askmaclean.com/thread-1484-1-1.html
10.2.0.5.0+RAC
Elapsed: 60.32 (mins)
DB Time: 582.45 (mins)
AAS非常高，说明负载很高
gc buffer busy 12,815,419 22,761 2 65.1 Cluster
CPU time 7,283 20.8
gc cr multi block request 14,317,933 2,828 0 8.1 Cluster
db file scattered read 1,530,336 1,697 1 4.9 User I/O
db file parallel read 304,600 440 1 1.3 User I/O
gc buffer busy是主要等待事
Avg global enqueue get time (ms): 0.7
Avg global cache cr block receive time (ms): 1.0
Avg global cache current block receive time (ms): 1.2
Avg global cache cr block build time (ms): 0.0
Avg global cache cr block send time (ms): 0.0
Global cache log flushes for cr blocks served %: 3.3
Avg global cache cr block flush time (ms): 2.6
Avg global cache current block pin time (ms): 0.0
Avg global cache current block send time (ms): 0.0
Global cache log flushes for current blocks served %: 0.0
Avg global cache current block flush time (ms): 2.9
pin time +send time + flush time都不高
引起主要cluter wait time的语句是
24,214.65 81.44 29,732.24 4,617.86 15 5q65r47cqxd2a DELETE FROM DA_EXAMRECORD WHER..
DELETE FROM DA_EXAMRECORD WHERE RESULT_ID=:1 AND QUESTION_ID=:2
执行15次 ， 可能涉及大表的大量删除记录
Segments by Current Blocks Received
Total Current Blocks Received: 17,738,220
Captured Segments account for 100.0% of Total
Owner Tablespace Name Object Name Subobject Name Obj. Type Current Blocks Received %Total
ANJIAN ANJIAN DA_EXAMRECORD TABLE 16,075,103 90.62
DA_EXAMRECORD表占 总Current Blocks Received的90%
Segments by Global Cache Buffer Busy
% of Capture shows % of GC Buffer Busy for each top segment compared
with GC Buffer Busy for all segments captured by the Snapshot
Owner Tablespace Name Object Name Subobject Name Obj. Type GC Buffer Busy % of Capture
ANJIAN ANJIAN DA_EXAMRECORD TABLE 12,746,041 99.89
引起 Global Cache Buffer Busy 的确实是 表 DA_EXAMRECORD
建议 调优 语句：
DELETE FROM DA_EXAMRECORD WHERE RESULT_ID=:1 AND QUESTION_ID=:2