Explain Plan Command
The explain command displays the execution plan for a statement without actually executing the statement; it parses and optimizes the SQL, then presents its execution plan.
You can use this to tune a query for improved performance.
An SQL statement.
SQL Data Definition Language (DDL) statement have no known cost, and
thus do not require optimization. Because of this, the
does not work with DDL statements; attempting to
explain a DDL
statement such as
CREATE TABLE will generate a syntax error.
For more information about using the explain command, including a number of annotated examples, see Explain Plan.
splice> explain select * from t t1 where t1.i < (select max(i) from t t1);
The Explain Plan topic contains a number of examples that are described in detail.