You need to know about the query execution plan

Question

Is there a way to view the mysql / oracle query execution plan as java debugging. I want to know how mysql / oracle fulfills our query and what are the steps related to the execution.

Answer 1

For mysql you should use

EXPLAIN <query> 

eg.

 EXPLAIN SELECT * FROM tableX 

see mysql link

For the oracle there is something similar, but more detailed:

 EXPLAIN PLAN FOR <query> 

eg.

 EXPLAIN PLAN FOR SELECT * FROM tableX 

see also: link for oracle

Answer 2

For MySQL you want EXPLAIN : http://dev.mysql.com/doc/refman/5.0/en/explain.html

And on Oracle, this is EXPLAIN PLAN : http://docs.oracle.com/cd/B10500_01/server.920/a96533/ex_plan.htm