Update statistics / missing index

Question

The performance has been downgraded after the DB migration... The Query seems running slower than it used to be,
How can I update statistics / find missing index to fix it in Oracle?

Answer 1

hi....
after the importing of the db please run the compilation script below
SET HEAD OFF
SET FEEDBACK OFF
SET PAGESIZE 0
SPOOL COM.SQL
SELECT 'ALTER '|| OBJECT_TYPE||' '|| OBJECT_NAME ||' COMPILE ; ' FROM
USER_OBJECTS
WHERE STATUS = 'INVALID'
AND OBJECT_TYPE != 'PACKAGE BODY'
ORDER BY OBJECT_TYPE
SELECT 'ALTER PACKAGE '|| OBJECT_NAME ||' COMPILE BODY ; ' FROM USER_OBJECTS
WHERE STATUS = 'INVALID'
AND OBJECT_TYPE = 'PACKAGE BODY'
ORDER BY OBJECT_TYPE
spool off
@com.sql
SET HEAD ON
SET FEEDBACK ON
SET PAGESIZE 100
this will compile database objects such as packages, functions and rebuilds indexes
regards,
steved