Re: Declarative partitioning

Hi Ildar,

On 2016/05/16 22:12, Ildar Musin wrote:
> Hi Amit,
> 
> I'm running some experiments based on your infrastructure trying to
> optimize SELECT queries. At some point I need to get PartitionDesc for
> relation and to do it I'm using RelationGetPartitionDesc() function.
> Problem is that this function copies relcache data and it can be quite
> slow for large amounts (thousands) of partitions. The comment to the
> function says that we cannot use relation->rd_partdesc pointer to relcache
> because of possibility of relcache invalidation. Could you please tell is
> it possible that relcache invalidation occurs during SELECT/UPDATE/DELETE
> query?

Hmm, I think invalidation would not occur mid-query since it would have
acquired a lock on the table.  So the copying may be unnecessary though I
may be wrong.  I will study other similar code and see if that is so.

Thanks,
Amit