Re: Should we increase the default vacuum_cost_limit?

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Gavin Flower <GavinFlower@archidevsys.co.nz>
Cc: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, David Rowley <david.rowley@2ndquadrant.com>, Jeff Janes <jeff.janes@gmail.com>, Jeremy Schneider <schnjere@amazon.com>, Joe Conway <mail@joeconway.com>, Peter Geoghegan <pg@bowt.ie>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-03-09T21:06:33Z
Lists: pgsql-hackers
Gavin Flower <GavinFlower@archidevsys.co.nz> writes:
> Hope about  keeping the default unit of ms, but converting it to a 
> 'double' for input, but storing it as int (or long?) number of 
> nanoseconds.  Gives finer grain of control withouthaving to specify a 
> unit, while still allowing calculations to be fast?

Don't really see the point.  The only places where we do any calculations
with the value are where we're about to sleep, so shaving a few nanosec
doesn't seem very interesting.

			regards, tom lane


Commits

  1. Allow fractional input values for integer GUCs, and improve rounding logic.

  2. Reduce the default value of autovacuum_vacuum_cost_delay to 2ms.

  3. Revert "Increase the default vacuum_cost_limit from 200 to 2000"

  4. Convert [autovacuum_]vacuum_cost_delay into floating-point GUCs.

  5. Include GUC's unit, if it has one, in out-of-range error messages.

  6. Disallow NaN as a value for floating-point GUCs.

  7. Increase the default vacuum_cost_limit from 200 to 2000