ORACLE SQL执行计划

--explain查看SQL执行计划EXPLAIN PLAN FOR select count(*) from steven.AWEN_OGG_TEST;select * from table(dbms_xplan.display());--查看AWR和CURSOR中的执行计划select * from table(dbms_xplan.display_awr('&sqlid'));select * from table(dbms_xplan.display_cursor('&sqlid'));--查看内存中的执行计划select '| Operation |Object Name | Rows | Bytes| Cost |'as "Explain Plan in library cache:" from dualunion allselect rpad('| '||substr(lpad(' ',1*(depth-1))||operation||decode(options, null,'',' '||options), 1, 35), 36, ' ')||'|'||rpad(decode(id, 0, '----------------------------',substr(decode(substr(object_name, 1, 7), 'SYS_LE_', null, object_name)||' ',1, 30)), 31, ' ')||'|'|| lpad(decode(cardinality,null,' ',decode(sign(cardinality-1000), -1, cardinality||' ',decode(sign(cardinality-1000000), -1, trunc(cardinality/1000)||'K',decode(sign(cardinality-1000000000), -1, trunc(cardinality/1000000)||'M',trunc(cardinality/1000000000)||'G')))), 7, ' ') || '|' ||lpad(decode(bytes,null,' ',decode(sign(bytes-1024), -1, bytes||' ',decode(sign(bytes-1048576), -1, trunc(bytes/1024)||'K',decode(sign(bytes-1073741824), -1, trunc(bytes/1048576)||'M',trunc(bytes/1073741824)||'G')))), 6, ' ') || '|' ||lpad(decode(cost,null,' ', decode(sign(cost-10000000), -1, cost||' ',decode(sign(cost-1000000000), -1, trunc(cost/1000000)||'M',trunc(cost/1000000000)||'G'))), 8, ' ') || '|' as "Explain plan"from v$sql_plan spwhere sp.hash_value=&hash_value or sp.sql_id='&sqlid';--查看历史执行计划select distinct SQL_ID,PLAN_HASH_VALUE,to_char(TIMESTAMP,'yyyymmdd hh24:mi:ss') TIMESTAMPfrom dba_hist_sql_planwhere SQL_ID='&sqlid' order by TIMESTAMP;