This step involves sorting

This statement indicates that the query must sort the intermediate results before returning them to the user. Queries that specify DISTINCT, as well as queries that have an ORDER BY clause that cannot use an available index, require an intermediate sort. As stated earlier, the results are put into a worktable, and the worktable is then sorted.

The following example demonstrates a query that requires a sort:

Query:

SELECT DISTINCT state
FROM stores

SHOWPLAN:

STEP 1
The type of query is INSERT
The update mode is direct
Worktable created for DISTINCT
FROM TABLE
stores
Nested iteration
Table Scan
TO TABLE
Worktable 1

STEP 2
The type of query is SELECT
This step involves sorting
FROM TABLE
Worktable 1
Using GETSORTED Table Scan