[Info-Ingres] Automatic partitioninng and unique keyed tables

[Roy Hann]

<martin.bowes at ctsu.ox.ac.uk> wrote in message 
news:mailman.109.1176731768.20015.info-ingres at kettleriverconsulting.com...
> Hi Everyone,
>
> I'm running Ingres2006 +p12125 on a64.lnx
>
> Why is it that I cannot put an automatic partition on a  unique keyed
> table?
>
> As I understand it, the automatic partition is just there to scatter the
> data randomly amongst the partitions. So to retrieve data it must go and
> look in each partition. Surely uniqueness would actually help not hinder
> that task?

I could wait to let Karl tell us all for sure, but my supposition has always 
been that in general, the cost of verifying uniqueness when the confounding 
value could (in principle) appear in one any of 65,000 partitions is just 
too high.  Ingres is protecting you from doing something expensive.

My rule of thumb is that if the parser couldn't figure out where to look, 
partitioning will just make things slower.

Roy