Re: Add pg_walinspect function with block info columns

On Fri, Mar 17, 2023 at 7:33 AM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
>
> > IIUC, the concern raised so far in this thread is not just on the
> > performance of JOIN queries to get both block info and record level
> > info, but on ease of using pg_walinspect functions. If
> > pg_get_wal_block_info emits the record level information too (which
> > turns out to be 50 LOC more), one doesn't have to be expert at writing
> > JOIN queries or such, but just can run the function, which actually
> > takes way less time (3sec) to scan the same 5mn WAL records [3].
>
> That's exactly my concern, yes. As you say, it's not just the
> performance aspect. Requiring users to write a needlessly ornamental
> query is actively misleading. It suggests that block_ref is distinct
> information from the blocks output by pg_get_wal_block_info().

+1 for pg_get_wal_block_info emitting per-record WAL info too along
with block info, attached v2 patch does that. IMO, usability wins the
race here.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com