Re: Remove HeapTuple and Buffer dependency for predicate lockingfunctions - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Remove HeapTuple and Buffer dependency for predicate lockingfunctions
Date
Msg-id 20190731175052.av2kpjvicjs45pm4@alap3.anarazel.de
Whole thread Raw
In response to Re: Remove HeapTuple and Buffer dependency for predicate locking functions  (Thomas Munro <thomas.munro@gmail.com>)
List pgsql-hackers
Hi,

On 2019-07-31 09:57:58 +1200, Thomas Munro wrote:
> On Tue, Jun 25, 2019 at 6:02 AM Andres Freund <andres@anarazel.de> wrote:
> > Hm.  I wonder if we somehow ought to generalize the granularity scheme
> > for predicate locks to not be tuple/page/relation.  But even if, that's
> > probably a separate patch.
> 
> What do you have in mind?

My concern is that continuing to inferring the granularity levels from
the tid doesn't seem like a great path forward. An AMs use of tids might
not necessarily be very amenable to that, if the mapping isn't actually
block based.


> Perhaps you just want to give those things different labels, "TID
> range" instead of page, for the benefit of "logical" TID users?
> Perhaps you want to permit more levels?  That seems premature as long
> as TIDs are defined in terms of blocks and offsets, so this stuff is
> reflected all over the source tree...

I'm mostly wondering if the different levels shouldn't be computed
outside of predicate.c.

Greetings,

Andres Freund



pgsql-hackers by date:

Previous
From: Peter Geoghegan
Date:
Subject: Re: Patch for SortSupport implementation on inet/cdir
Next
From: Andres Freund
Date:
Subject: Re: Remove HeapTuple and Buffer dependency for predicate lockingfunctions