Re: Legacy GiST invalid tuples

> 4 июля 2018 г., в 19:22, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> написал(а):
>
> Andrey Borodin <x4mmm(at)yandex-team(dot)ru> writes:
>> There is bunch of code in current GiST implementation checking for GistTupleIsInvalid(). PostgreSQL since 9.1 do not create invalid tuples. Should we support this tuples forever?
>
> The question is not whether we still create such tuples. The reason
> the code is still there is that an index that's been pg_upgraded from
> before 9.1 might still contain such tuples. We can't drop the support
> unless either we provide logic to clean up invalid entries, or we're
> willing to force users to REINDEX old GiST indexes to get rid of them
> that way. The latter seems like a pretty high price just to get rid of
> some crufty old code.

Thanks, Tom!

So, I can create the script for pg_upgrade that will walk through each old enough[0] GiST index, scan for invalid tuples and repair them. This procedure seems quite trivial, but there will be more code that we have now. Does it sound reasonable?

[0] Actually, I do not know how to understand which index is old enough.

Best regards, Andrey Borodin.