Re: HashAgg degenerate case

From: David Rowley <dgrowleyml(at)gmail(dot)com>
To: Jeff Davis <pgsql(at)j-davis(dot)com>
Cc: pgsql-bugs(at)postgresql(dot)org
Subject: Re: HashAgg degenerate case
Date: 2024-11-06 02:50:50
Message-ID: CAApHDvr3byTEhJ+yZb91t3OqAHtsyADUea2Xe2zCnw+G4k0RpA@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

On Wed, 6 Nov 2024 at 14:00, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:
> Fixing it seems fairly easy though: we just need to completely destroy
> the hash table each time and recreate it. Something close to the
> attached patch (rough).

I don't think it could be that exactly though as that could lead to
JIT compilation over and over again from the following chain of
function calls: build_hash_tables() -> build_hash_table() ->
BuildTupleHashTableExt() -> ExecBuildGroupingEqual() ->
ExecReadyExpr() -> jit_compile_expr()

David

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message PG Bug reporting form 2024-11-06 08:57:20 BUG #18690: A count function returns wrong value when using FDW
Previous Message Jeff Davis 2024-11-06 00:59:56 HashAgg degenerate case