PLAN function [Miscellaneous]

Returns the long plan optimization strategy of a SQL statement, as a string.

PLAN ( string-expression, [ cursor-type ], [ update-status ] )

string-expression The SQL statement, which is commonly a SELECT statement but which may also be an UPDATE or DELETE.

cursor-type A string. Cursor-type can be asensitive (default), insensitive, sensitive, or keyset-driven.

update-status A string parameter accepting one of the following values indicating how the optimizer should treat the given cursor:

Value	Description
READ-ONLY	The cursor is read-only.
READ-WRITE (default)	The cursor can be read or written to.
FOR UPDATE	The cursor can be read or written to. This is exactly the same as READ-WRITE.

The following statement passes a SELECT statement as a string parameter and returns the plan for executing the query.

SELECT PLAN(
   'SELECT * FROM department WHERE dept_id > 100' )

This information can help with decisions about indexes to add or how to structure your database for better performance.

The following statement returns a string containing the textual plan for an INSENSITIVE cursor over the query 'select * from department where ...'.

SELECT PLAN(
   'SELECT * FROM department WHERE dept_id > 100',
   'insensitive',
   'read-only' )

In Interactive SQL, you can view the plan for any SQL statement on the Plan tab in the Results pane.