Re: Patch: add timing of buffer I/O requests

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Geoghegan <peter@2ndquadrant.com>
Cc: Greg Smith <greg@2ndquadrant.com>, Magnus Hagander <magnus@hagander.net>, Robert Haas <robertmhaas@gmail.com>, Ants Aasma <ants@cybertec.at>, pgsql-hackers@postgresql.org
Date: 2012-04-10T23:17:30Z
Lists: pgsql-hackers
Peter Geoghegan <peter@2ndquadrant.com> writes:
> On 10 April 2012 23:07, Greg Smith <greg@2ndquadrant.com> wrote:
>> On 04/10/2012 12:27 PM, Tom Lane wrote:
>> I am doing more sophisticated things with it, so I'll celebrate this as my
>> opportunity to say I did something you didn't see coming for 2012.

> This is why I requested that we expose the query_id hash value - I
> believe that it will be generally useful in clustering situations. It
> would be nice to have a persistent identifier. While we're discussing
> revising pg_stat_statement's interface, are you still opposed to
> exposing that value, Tom?

I still am.  I'm unconvinced by references to "clustering situations",
because as constructed the hash is extremely database-specific.
It will vary depending on OID assignments, not to mention platform
characteristics such as word width and endianness.

			regards, tom lane