1.
慢SQL导致业务响应失败
2.TOP 10等待与gc,libcache lock/pin相关
3.ADDM硬解析
4. TOP等待包括大量后端进程等待
5. SQL by parse
//TOP数据字典查询
select /* KSXM:LOAD_DML_INF *//*+ leading(o) index(m) use_nl(m) */ nvl(m.inserts, 0) ins, nvl(m.updates, 0) upd, nvl(m.deletes, 0) del, nvl(m.drop_segments, 0) dropseg, nvl(m.flags, 0) flags, nvl(rowcnt, 0) rowcnt, o.pobjn pobjn from (select :objn objn, 0 pobjn, rowcnt from tab$ t where t.obj# = :objn union all select :objn objn, tp.bo# pobjn, rowcnt from tabpart$ tp where tp.obj# = :objn union all select :objn objn, tcp.bo# pobjn, rowcnt from tabcompart$ tcp where tcp.obj# = :objn union all select :objn objn, tsp.pobj# pobjn, rowcnt from tabsubpart$ tsp where tsp.obj# = :objn) o, sys.mon_mods_all$ m where o.objn = m.obj#(+) and rownum < 2
6. Mutex Sleep Summary
7. Version count700+
8.ASH有lgwr等待
9.优化方法，优化参数
alter system set "_use_single_log_writer"=FALSE sid='*' scope=spfile; alter system set "_use_adaptive_log_file_sync"=FALSE sid='*' scope=spfile; alter system set "_gc_policy_time"=0 sid='*' scope=spfile; alter system set "_gc_undo_affinity"=FALSE sid='*' scope=spfile; alter system set "_cursor_obsolete_threshold" =1024 sid='*' scope=spfile; alter system set "_optimizer_extended_cursor_sharing"='NONE' sid='*'; alter system set "_optimizer_extended_cursor_sharing_rel"='NONE' sid='*'; alter system set "_optimizer_adaptive_cursor_sharing"=FALSE sid='*'; alter system set "_optimizer_use_feedback"=false sid='*';
10.优化效果对比
//解析
//version count
11.调优后TOP等待*（libcache/parse相关已优化）
