Horton

Re: 64-bit queryId?

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Greg Stark <stark@mit.edu>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Peter Geoghegan <pg@bowt.ie>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2017-10-01T23:22:20Z
Lists: pgsql-hackers 
On Sun, Oct 1, 2017 at 3:48 PM, Greg Stark <stark@mit.edu> wrote:
> Well these kinds of monitoring systems tend to be used by operations
> people who are a lot more practical and a lot less worried about
> theoretical concerns like that.

+1, well said.

> In context the point was merely that the default
> pg_stat_statements.max of 5000 isn't sufficient to argue that 32-bit
> values are enough. It wouldn't be hard for there to be 64k different
> queries over time and across all the databases in a fleet and at that
> point it becomes likely there'll be a 32-bit collision.

Yeah.

I think Alexander Korotkov's points are quite good, too.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. pg_stat_statements: Add a comment about the dangers of padding bytes.

  2. pg_stat_statements: Widen query IDs from 32 bits to 64 bits.