Re: Re: [HACKERS] [COMMITTERS] pgsql: Fix TransactionIdIsCurrentTransactionId() to use binary search

On Friday 25 April 2008 17:32, Tom Lane wrote:
> Robert Treat <xzilla(at)users(dot)sourceforge(dot)net> writes:
> > Oddly some dtrace profiling gave me this, which is pretty different, but
> > certainly doesn't have concerns about TransactionIdIsCurrentTransactionId
>
> .... which seems to pretty much destroy your thesis, no?
>

How so? Before the patch we bog down for hours, spending 99% of our time in
TransactionIdIsCurrentTransactionId, after the patch everything performs well
(really better than before) and we spend so little time in
TransactionIdIsCurrentTransactionId it barely shows up on the radar.

Note I'm open to the idea that TransactionIdIsCurrentTransactionId itself is
not the problem, but that something else changed between 8.1 and 8.3 that
exposes TransactionIdIsCurrentTransactionId as a problem. Changing to a
binary search for TransactionIdIsCurrentTransactionId makes that a non-issue
though.

--
Robert Treat
Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL