MIME-Version: 1.0
References: 
 <CAApHDvpbntG7V3_EsZ+w-V=jU-y8rFmv9RB1EDJm4sxKno-4UA@mail.gmail.com>
 <e7sto7tk5dk5hfyvoocaddnxcngemcmfvbuh23l32w5cssaizy@znuphjqug7qe>
 <CAApHDvpuEbhvH1ViCZRz5vks+_bGbEnPoEdZYAZXK76_isb_+Q@mail.gmail.com>
 <v6z545yozjtywghn5glujemu72z4i4ynadsc2xks4ejotdg7yl@4rry7ixwr4us>
 <CANWCAZabO1oj+khF+YNVpmkTQwRRyNJesbsBhRFL5emZJh3tow@mail.gmail.com>
 <lzgoxzbh2gel5w362revuwaecrsbjr44kjdzrewuejugcodkeq@ixymojwnylsy>
 <CAApHDvodSVBj3ypOYbYUCJX+NWL=VZs63RNBQ_FxB_F+6QXF-A@mail.gmail.com>
 <rbxc2qqhsvzxpukgd36caoa4ydgn5r22fxktxanrkn6nobg7j6@27b4vogohgu2>
 <CAApHDvpWQn8sXDYpSNNpieJW-UTG4Nf4TVjT8ew64L073hz-Fw@mail.gmail.com>
 <mq6ddpgctt42srolsvo5kph2s6shfg62meb7i5fbg6n3s73zju@2n7gviiyga3h>
 <uhqul2ryci4tyg5ylddjrmf4kybzwb7m5z7rmurhhjp37vrn5f@zgxil7egr62n>
 <CAApHDvq21qQigiM6z2YgadFusQC_pfEYP8D=oQCrwJ_kKzcqDg@mail.gmail.com>
 <CAApHDvpdB1t7LCgH8=KOKC6VBb2rsEbaas0FiXo5awsRgCsDxQ@mail.gmail.com>
 <CAEG8a3KeKcZxJsH9nL+D1JzC4Ekx51ps7-1ZGWkwdXbPS5jTXw@mail.gmail.com>
 <CAApHDvqp_DGNkz3Rr29hPuSYdai5c_32mWSv2inrW2ufsE+qZQ@mail.gmail.com>
 <CAHewXNnb-s_=VdVUZ9h7dPA0u3hxV8x2aU3obZytnqQZ_MiROA@mail.gmail.com>
 <CAApHDvrFmW+2GhdDKuWRaJmp8MfghmBiEGaeqjOD_Y2RWUFSow@mail.gmail.com>
 <CAApHDvoy9AJ4D2+pJE0ZRhPPCHh-Mm-sZAfookKtf_3V+GeP0g@mail.gmail.com>
 <CAHewXNmSK+gKziAt_WvQoMVWt3_LRVMmRYY9dAbMPMcpPV0QmA@mail.gmail.com>
 <CAApHDvo-5T5Wn1nxUhOsjtYvAbmUPaFpxyLePtyG+6O5hxOb4w@mail.gmail.com>
In-Reply-To: 
 <CAApHDvo-5T5Wn1nxUhOsjtYvAbmUPaFpxyLePtyG+6O5hxOb4w@mail.gmail.com>
From: David Rowley <dgrowleyml@gmail.com>
Date: Fri, 20 Mar 2026 14:18:12 +1300
Message-ID: 
 <CAApHDvpdAXFdKeDaMDf1ssvSc-38-POg8QRBTKHEg7dhGRXP-g@mail.gmail.com>
Subject: Re: More speedups for tuple deformation
To: Tender Wang <tndrwang@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, John Naylor <johncnaylorls@gmail.com>,
	PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: 
 <https://www.postgresql.org/message-id/CAApHDvpdAXFdKeDaMDf1ssvSc-38-POg8QRBTKHEg7dhGRXP-g%40mail.gmail.com>
Precedence: bulk

On Fri, 20 Mar 2026 at 01:56, David Rowley <dgrowleyml@gmail.com> wrote:
>
> On Fri, 20 Mar 2026, 01:39 Tender Wang, <tndrwang@gmail.com> wrote:
>> 1197 pg_assume(attlen > 0 || attlen =3D=3D -1);
>> (gdb) p attlen
>> $1 =3D -2
>
>
> Thanks for the report. I'll look in detail in the morning when I'm at my =
computer again. I guess i'll need to add an extra parameter (that will be c=
onstant folded away during the inlining) to the deformed function to specif=
y if cstrings can exist in the tuple, which seemingly needs to be true when=
 deforming minimal tuples. I'd rather not lose that optimisation with heap =
tuples.

I've pushed a fix for this.  A more simple recreator was:

with cte as materialized (select relname::cstring as relname from
pg_class) select relname from cte;

David