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Re: Amcheck verification of GiST and GIN

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Nikolay Samokhvalov <samokhvalov@gmail.com>
Cc: Andrey Borodin <amborodin86@gmail.com>, Jose Arthur Benetasso Villanova <jose.arthur@gmail.com>, Andres Freund <andres@anarazel.de>, Andrey Borodin <x4mmm@yandex-team.ru>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-02-02T23:16:32Z
Lists: pgsql-hackers 
On Thu, Feb 2, 2023 at 12:56 PM Nikolay Samokhvalov
<samokhvalov@gmail.com> wrote:
> I already realized my mistake – indeed, having multiple errors for 1 index
> doesn't seem to be super practically helpful.

I wouldn't mind supporting it if the cost wasn't too high. But I
believe that it's not a good trade-off.

>> I think that that problem should be solved at a higher level, in the
>> program that runs amcheck. Note that pg_amcheck will already do this
>> for B-Tree indexes.
>
>
> That's a great tool, and it's great it supports parallelization, very useful
> on large machines.

Another big advantage of just using pg_amcheck is that running each
index verification in a standalone query avoids needlessly holding the
same MVCC snapshot across all indexes verified (compared to running
one big SQL query that verifies multiple indexes). As simple as
pg_amcheck's approach is (it's doing nothing that you couldn't
replicate in a shell script), in practice that its standardized
approach probably makes things a lot smoother, especially in terms of
how VACUUM is impacted.

-- 
Peter Geoghegan

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. amcheck: Fix posting tree checks in gin_index_check()

  2. amcheck: Fix parent key check in gin_index_check()

  3. amcheck: Fix checks of entry order for GIN indexes

  4. amcheck: Remove unused GinScanItem->parentlsn field

  5. amcheck: Test gin_index_check on a multicolumn index

  6. Remove incidental md5() function use from test

  7. amcheck: Add a GIN index to the CREATE INDEX CONCURRENTLY tests

  8. amcheck: Add a test with GIN index on JSONB data

  9. amcheck: Fix indentation in verify_gin.c

  10. amcheck: Add gin_index_check() to verify GIN index

  11. amcheck: Move common routines into a separate module

  12. Fix grammar in GIN README

  13. Avoid amcheck inline compression false positives.