Re: A problem about partitionwise join - Mailing list pgsql-hackers

From Richard Guo
Subject Re: A problem about partitionwise join
Date
Msg-id CAMbWs49akrNX-iLmCnpifd52YxeP07dHiBnS-uyt=OnUzH1kpQ@mail.gmail.com
Whole thread Raw
In response to Re: A problem about partitionwise join  (Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>)
List pgsql-hackers
On Mon, Mar 25, 2024 at 7:09 PM Ashutosh Bapat
<ashutosh.bapat.oss@gmail.com> wrote:
> I think we need some way to avoid two different ways of looking up partition keys - if we can't teach the EC
machineryto produce clauses with partition keys (always), we need to teach EC to contain partition keys in case of
outerjoins. Tom alluded to this but I haven't seen any proposal. The potential danger with the current patch is that it
willcontinue to have two loops even if we fix one of the above cases in future. 

Sorry for not replying to this comment before pushing the patch.  I
understand your concern and agree that it would be ideal if the
partitionwise join matching logic relied solely on ECs.  However,
implementing that would require a lot of changes to the EC mechanism,
and I'm not sure if that will happen in the near future.  And if we do
achieve this in the future, I believe many parts of the code, not just
the loops here, will need to be modified to leverage the new EC
mechanism.

Thanks
Richard



pgsql-hackers by date:

Previous
From: David Rowley
Date:
Subject: Re: Do we still need parent column in pg_backend_memory_context?
Next
From: Amit Kapila
Date:
Subject: Re: Conflict detection and logging in logical replication