Re: DWH : Index on Partition Key s

  • From: Stephane Faroult <sfaroult@xxxxxxxxxxxx>
  • To: hkchital@xxxxxxxxxxxxxx
  • Date: Fri, 30 Oct 2009 16:48:53 +0100


I don't see the point if you have any prefixed local index, but if you
have none, if you have one partition by month and most queries hit a
single day or less, then this index *might*, depending on volume, etc,
etc. benefit those queries.
But then perhaps you could begin to question the partition grain ...

By the way a lot of developers seem never to have been told that you
could index several columns at once. Or it's just the developers that
work on the applications I have to audit.

S Faroult

Hemant K Chitale wrote:
> Would there be any reason to create a single column index on the
> PARTITION_KEY column  (which is a VARCHAR2 representation of a date
> --- I know, I know, bear with me !)  ?
> So, we have 24 PARTITION_KEY values for the 24 months that we are
> holding data.
> Why have a single-column index on PARTITION_KEY ?
> (no this isn't a trick question :  I am really confused by this design
> that I see having been implemented).
> Hemant K Chitale


Other related posts: