Export / Import Can Be Very Slow with Optimizer_Mode = first_ROWSHTTP: / /METALINK.OrCle.com/Metalink/PLSQL / ML2_DOCUMENTS.SHOWDOCUMENT? P_DATABASE_ID = NOT & P_ID = 181072.1
Solution: Option 1. Modify the application's SQL to make SQL apply to Optimizer_Mode = Choose2. Modify the application SQL, add "/ * first_rows * /" prompt 3. Modify the initialization parameters OPTIMIZER_MODE = CHOOSE, creating logon trigger only when the user logs before application optimization mode settings CREATE OR REPLACE TRIGGER LoginTrigger AFTER LOGON ON ETFDB.SCHEMA BEGIN execute immediate 'alter session set OPTIMIZER_GOAL = FIRST_ROWS'; END; / 4 . Expimpadmin uses specialized user EXPIMPADMIN, which has exp_full_database and omp_full_database roles. Then create a trigger Create or Replace Trigger LogintriggerAfter Logon on Expimpadmin.schemabegin Expimpadmin.schemabegin Execute Immediate 'ALTER Session Set Optimizer_Goal = Choose'; END; /
It is recommended to use the third way.
