The WITH XMLPLAN option of the BEGIN QUERY LOGGING statement provides more detailed Optimizer query plan information than the INSERT EXPLAIN statement modifier. That plan information, structured and stored as an XML document, can be easily parsed and analyzed by those reading the log.
The XMLPLAN option does not log query plans for EXPLAIN request modifiers, DDL requests, or for the INSERT EXPLAIN and DUMP EXPLAIN statements.
Query plan logging has benefits:
- It does not require users to create a separate database to capture query plans.
- It allows users to capture the plans for a set of queries easily via a single BEGIN QUERY LOGGING or REPLACE QUERY LOGGING statement rather than having to issue a separate INSERT EXPLAIN or DUMP EXPLAIN statement for each one.
- It provides more plan details than the INSERT EXPLAIN modifier.