Re: Large files for relations

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: Thomas Munro <thomas.munro@gmail.com>, Stephen Frost <sfrost@snowman.net>
Cc: Robert Haas <robertmhaas@gmail.com>, Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>, Jim Mlodgenski <jimmy76@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2023-05-30T11:20:54Z
Lists: pgsql-hackers
On 28.05.23 02:48, Thomas Munro wrote:
> Another potential option name would be --segsize, if we think we're
> going to use this for temp files too eventually.
> 
> Maybe it's not so beautiful to have that global variable
> rel_segment_size (which replaces REL_SEGSIZE everywhere).  Another
> idea would be to make it static in md.c and call smgrsetsegmentsize(),
> or something like that.

I think one way to look at this is that the segment size is a 
configuration property of the md.c smgr.  I have been thinking a bit 
about how smgr-level configuration could look.  You can't use a catalog 
table, but we also can't have smgr plugins get space in pg_control.

Anyway, I'm not asking you to design this now.  A global variable via 
pg_control seems fine for now.  But it wouldn't be an smgr API call, I 
think.