On Wed, Jun 26, 2024 at 4:57 PM Tomas Vondra <tomas.von...@enterprisedb.com> wrote: > > On 6/25/24 07:04, Amit Kapila wrote: > > On Mon, Jun 24, 2024 at 8:06 PM Tomas Vondra > > <tomas.von...@enterprisedb.com> wrote: > >> > >> On 6/24/24 12:54, Amit Kapila wrote: > >>> ... > >>>> > >>>>>> I'm not sure there are any cases where using SRE instead of AE would > >>>>>> cause > >>>>>> problems for logical decoding, but it seems very hard to prove. I'd be > >>>>>> very > >>>>>> surprised if just using SRE would not lead to corrupted cache contents > >>>>>> in some > >>>>>> situations. The cases where a lower lock level is ok are ones where we > >>>>>> just > >>>>>> don't care that the cache is coherent in that moment. > >>>> > >>>>> Are you saying it might break cases that are not corrupted now? How > >>>>> could obtaining a stronger lock have such effect? > >>>> > >>>> No, I mean that I don't know if using SRE instead of AE would have > >>>> negative > >>>> consequences for logical decoding. I.e. whether, from a logical decoding > >>>> POV, > >>>> it'd suffice to increase the lock level to just SRE instead of AE. > >>>> > >>>> Since I don't see how it'd be correct otherwise, it's kind of a moot > >>>> question. > >>>> > >>> > >>> We lost track of this thread and the bug is still open. IIUC, the > >>> conclusion is to use SRE in OpenTableList() to fix the reported issue. > >>> Andres, Tomas, please let me know if my understanding is wrong, > >>> otherwise, let's proceed and fix this issue. > >>> > >> > >> It's in the commitfest [https://commitfest.postgresql.org/48/4766/] so I > >> don't think we 'lost track' of it, but it's true we haven't done much > >> progress recently. > >> > > > > Okay, thanks for pointing to the CF entry. Would you like to take care > > of this? Are you seeing anything more than the simple fix to use SRE > > in OpenTableList()? > > > > I did not find a simpler fix than adding the SRE, and I think pretty > much any other fix is guaranteed to be more complex. I don't remember > all the details without relearning all the details, but IIRC the main > challenge for me was to convince myself it's a sufficient and reliable > fix (and not working simply by chance). > > I won't have time to look into this anytime soon, so feel free to take > care of this and push the fix. >
Okay, I'll take care of this. -- With Regards, Amit Kapila.
