Robert Haas writes:
> On Mon, Oct 11, 2010 at 10:14 AM, Tom Lane wrote:
>> Reduction of contention for pg_clog access, for one thing. If you read
>> the archives, you'll find that pg_clog access contention has been shown
>> to be one cause of "context swap storms".
> I wonder if we could improv
> I wonder if we could improve this with some sort of process-local
> cache - not to get rid of hint bits, just to reduce pg_clog
> contention. We might easily end up testing the same XID many times
> during the same table scan.
I guess that's my scenario... not that many transactions, so ev
On Mon, Oct 11, 2010 at 10:14 AM, Tom Lane wrote:
> Reduction of contention for pg_clog access, for one thing. If you read
> the archives, you'll find that pg_clog access contention has been shown
> to be one cause of "context swap storms".
I wonder if we could improve this with some sort of pro
> Reduction of contention for pg_clog access, for one thing. If you read
> the archives, you'll find that pg_clog access contention has been shown
> to be one cause of "context swap storms". Having to go to clog for
> every single tuple access would make that orders of magnitude worse.
Ok;
Leonardo Francalanci writes:
> I was wondering what is the advantage of having hint bits for OLAP
> -style workloads, that is when the number of transactions is not
> that high.
> If I got it right, in 10 pg_clog pages we can store the status for more
> than 32 transactions. That's a lot, in
