Jeff,
> Right now they are just constants defined in a header, but a GUC might
> make sense. I'd like to know which version is more acceptable when I
> submit my final patch.
As much as I hate the thought of more GUCs, until we have a solid
performance profile for synch scan we probably need them. You should
include the option to turn synch_scan off, such as by setting
synch_scan_threshold to -1.
Oh, and remember that these now need to be able to take K/MB/GB.
These options should probably go in postgresql.conf under QUERY TUNING,
with their own sub-head.
--
--Josh
Josh Berkus
PostgreSQL @ Sun
San Francisco