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

Peter Geoghegan <peter(at)2ndquadrant(dot)com> writes:
> On 11 April 2012 00:35, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> If people need something like that, couldn't they create it by hashing
>> the normalized query text with an arbitrary algorithm?

> That supposes that the normalised query text is perfectly stable. It
> may well not be, particularly for things like ad-hoc queries or
> queries generated by ORMs, across database clusters and over long
> periods of time -

Indeed, but the hash value isn't stable either given those sorts of
assumptions, so I'm not convinced that there's any advantage there.

What I think people would actually like to know, if they're in a
situation where distinct query texts are getting hashed to the same
thing, is *which* different texts got hashed to the same thing.
But there's no good way to expose that given the pg_stat_statements
infrastructure, and exposing the hash value doesn't help.

regards, tom lane