Re: Initdb-time block size specification

On 6/30/23 23:11, Andres Freund wrote:
> Hi,
>
> ...
> 
> I suspect you're going to see more benefits from going to a *lower* setting
> than a higher one. Some practical issues aside, plenty of storage hardware
> these days would allow to get rid of FPIs if you go to 4k blocks (although it
> often requires explicit sysadmin action to reformat the drive into that mode
> etc).  But obviously that's problematic from the "postgres limits" POV.
> 

I wonder what are the conditions/options for disabling FPI. I kinda
assume it'd apply to new drives with 4k sectors, with properly aligned
partitions etc. But I haven't seen any particularly clear confirmation
that's correct.

> 
> If we really wanted to do this - but I don't think we do - I'd argue for
> working on the buildsystem support to build the postgres binary multiple
> times, for 4, 8, 16 kB BLCKSZ and having a wrapper postgres binary that just
> exec's the relevant "real" binary based on the pg_control value.  I really
> don't see us ever wanting to make BLCKSZ runtime configurable within one
> postgres binary. There's just too much intrinsic overhead associated with
> that.
> 

How would that work for extensions which may be built for a particular
BLCKSZ value (like pageinspect)?


regards

-- 
Tomas Vondra
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