Archives of the TeradataForum

Message Posted: Mon, 11 Dec 2007 @ 00:56:43 GMT

	<Prev	Next>		<<First	<Prev	Next>	Last>>

I know it's not supposed to be this way, but I have noticed anecdotally (pre-v2r6, haven't checked on this version) that the optimizer often made better decisions based on stats on an index on a column than it did stats on just the column itself, even if it did not then use the index for selection.

This makes me do basic things like always making sure FK columns have an index and stats, because it can make the difference between a small table selection or not. Rule of thumb should be, try stats on column, then try index/stats on the column, and see which one works best. If it's a wash, just keep the stats.

Regards,

Dave

David W. Roth
Teradata Certified Master
TERADATA

	<Prev	Next>		<<First	<Prev	Next>	Last>>