The EXPLAIN PLAN results let you determine whether the optimizer selects a particular execution plan, such as, nested loops join. It also helps you to understand the optimizer decisions, such as why the optimizer chose a nested loops join instead of a hash join, and lets you understand the performance of a query.

What does explain plan do in Oracle?

The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT , UPDATE , INSERT , and DELETE statements. A statement's execution plan is the sequence of operations Oracle performs to run the statement.

What is explain plan in DML?

The EXPLAIN PLAN statement is a data manipulation language (DML) statement, rather than a data definition language (DDL) statement. Therefore, Oracle Database does not implicitly commit the changes made by an EXPLAIN PLAN statement. ... If you omit schema , then the database assumes the table is in your own schema.