Poor index identify and resolve manually or using sql tuning advisor

1.Let us create a test case first:- oracle@TST:TESTDB1[/home/oracle]$ sqlplus c##test/test C##TEST@TESTDB1> create table mytst1 as select * from dba_objects; Table created. C##TEST@TESTDB1> create table mytst2 as select * from dba_objects where rownum<5000; Table created. 2.Let us see what application executes SQL query and complaining poor performance select a.owner,a.OBJECT_NAME,a.OBJECT_TYPE,b.STATUS from mytst1 a,mytst2 b where a.OBJECT_ID=b.OBJECT_ID andContinue reading Poor index identify and resolve manually or using sql tuning advisor

ORACLE OPTIMIZER COST CALCULATIONS BASIC OVERVIEW

Cost Calculation for Full table Scan How FTS cost depends on system statistics Gather statistics manually on load: The following command will start to gather system statistics. SQL> execute DBMS_STATS.GATHER_SYSTEM_STATS (‘START’); Please wait for system warm up and stop gather system statistics after work load. This is called workload statistics. The MBRC will be calculatedContinue reading ORACLE OPTIMIZER COST CALCULATIONS BASIC OVERVIEW