Re: pg_sequence catalog

On 2016-08-31 13:59:48 -0400, Tom Lane wrote:
> andres@anarazel.de (Andres Freund) writes:
> > On 2016-08-31 14:25:43 -0300, Alvaro Herrera wrote:
> >> Yes, sure, we're still improving even if we stick to one-seq-per-bufpage,
> >> but while we're at it, we could as well find a way to make it as best as
> >> we can.  And allowing multiple seqs per page seems a much better
> >> situation, so let's try to get there.
> 
> > It's not really that simple. Having independent sequence rows closer
> > together will have its own performance cost.
> 
> You are ignoring the performance costs associated with eating 100x more
> shared buffer space than necessary.

I doubt that's measurable in any real-world scenario. You seldomly have
hundreds of thousands of sequences that you all select from at a high
rate.