I am dissecting a SQL statement and cannot find out what the "parse_activity" statement does

Question

I am dissecting a SQL statement and cannot find out what the "parse_activity" statement does. I can find nothing with the following syntax:

WITH PARSE_ACTIVITY AS (
    SELECT C.SOURCE_ID SUBMISSION_ID, C.NEED_BY_DT, C.PENDING_DT, C.ASSIGNED_DT,
           A.CREATE_HID, A.WORKFLOW_ACTIVITY_ID, A.WORKFLOW_COMMENT_ID, A.BUS_DIVISION_CD *.... etc....*

Answer 1

What you're looking at is known as a Common Table Expression (CTE).

For use of CTEs in Oracle, see http://www.morganslibrary.org/reference/with.html

For use of CTEs in Microsoft SQL Server, see: http://msdn.microsoft.com/en-us/library/ms175972.aspx