We have to run the analyze command during off peak time only because it actually performs full table scan.
Bulk sql are forall and bulk collect INTO statement,
For performence reason the bulk bind is used to eleminate the context switching between two sql and pl/sql eng.
mutated trigger: example:Table A has an insert trigger.In that Trigger: There is a statement like insert into Table A, which caues mutated trigger.Avoid to have those kind of triggers in the database.
Use DBMS_JOB/DBMS_SCHEDULER and give the Job_type as EXECUTABLE and give the path name of the shell script to execute.
The built-in function SYSDATE returns a DATE value containing the current date and time on your system. DUAL is built-in relation in Oracle which serves as a dummy relation to put in the FROM clause when nothing else is appropriate. For example, try "select 1+2 from dual;".So "select sysdate from EMP" won't generate the desired result.
Select sysdate from emp will not return any error.. It will return sysdate in all the rows. i.e if emp has 100 rows sysdate will be returned 100 times