On Fri, Nov 8, 2024 at 4:05 AM Tom Lane <tgl@sss.pgh.pa.us> wrote: > Alexander Korotkov <aekorotkov@gmail.com> writes: > > On Thu, Nov 7, 2024 at 8:47 AM Tender Wang <tndrwang@gmail.com> wrote: > >> Based on Tom's analysis, I provide a POC patch. I'm not sure if it is right > >> to use DEFAULT_COLLATION_OID in the patch. > > > Thank you. But I'm not sure about DEFAULT_COLLATION_OID. > > I don't quite trust that either. But since we only care about > equality, wouldn't it be OK to use C_COLLATION_OID? > > > Therefore, we can compare two text[] just with datumIsEqual(). > > Attached patch implements this. > > I think this is nonsense. What about toasted datums, or even > just short-header ones? The one coming from an on-disk tuple > is pretty likely to be short-header for plausible sizes of > the options, but the one we just constructed in memory will > not be.
You are correct. I quickly skim trough the sources and didn't find a function which compares detoasted contents of Datums excluding headers. So, yes, comparison using C-collation seems the most reasonable option.
