通过v$sqlarea,v$sql查询最占用资源的查询
----------------------- v$sqlarea,v$sql -----------------------
从V$SQLAREA中查询最占用资源的查询
select b.username username,a.disk_reads reads, a.executions exec,a.disk_reads/decode(a.executions,0,1,a.executions) rds_exec_ratio, a.sql_text Statement from v$sqlarea a,dba_users b where a.parsing_user_id=b.user_id and a.disk_reads > 100000 order by a.disk_reads desc;
用buffer_gets列来替换disk_reads列可以得到占用最多内存的sql语句的相关信息。
V$SQL是内存共享SQL区域中已经解析的SQL语句。
列出使用频率最高的5个查询:
select sql_text,executions from (select sql_text,executions, rank() over (order by executions desc) exec_rank from v$sql) where exec_rank <=5;
消耗磁盘读取最多的sql top5: select disk_reads,sql_text from (select sql_text,disk_reads, dense_rank() over (order by disk_reads desc) disk_reads_rank from v$sql) where disk_reads_rank <=5;
找出需要大量缓冲读取(逻辑读)操作的查询:
select buffer_gets,sql_text from (select sql_text,buffer_gets, dense_rank() over (order by buffer_gets desc) buffer_gets_rank from v$sql) where buffer_gets_rank<=5;
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