Archives of the TeradataForum
Message Posted: Thu, 21 May 2009 @ 14:47:37 GMT
Does Teradata optimizer need the select columns in a subquery to create a derived table to be in a specific order?
Assume the following -
SEL .... FROM A Join (Sel
Does it use the first column in the derived table B as the PI OR does the optimizer understand that regardless of location of B.Col1, that needs to be driver for distribution / hashing? I understand that with standalone "Create Tables As", this is a factor and that first column either be the PI column, or PI be explicitly specified. But with a derived table, where optimizer has access to statistics and query, does it still need the user specify the order?
|Copyright 2016 - All Rights Reserved|
|Last Modified: 28 Jun 2020|