Re: Amcheck verification of GiST and GIN - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: Amcheck verification of GiST and GIN
Date
Msg-id 5afb10c2-fd99-4e28-bf4a-4a4a98707485@vondra.me
Whole thread Raw
In response to Amcheck verification of GiST and GIN  (Andrey Borodin <x4mmm@yandex-team.ru>)
Responses Re: Amcheck verification of GiST and GIN
List pgsql-hackers
Hello Arseniy,

I finally got time to look at this more closely, and do some testing.

Are there any cases when the current code incorrectly reports corruption
for a valid index? So far I've been unable to find such case. Or am I wrong?

It seems to me all the proposed changes are "tightening" the checks, in
the sense that we might have missed certain types of issues before. This
is supported by the fact that the new TAP test fails on master, i.e.
master does not report the corruption the TAP introduces.

(The TAP test is great, it would have been great to add something like
this in the original commit.)

Also, I've noticed that the TAP test passes even with some (most) of the
verify_gin.c changes reverted. See the 0002 patch - this does not break
the TAP test. Of course, that does not prove the changes are wrong and
I'm not claiming that. But can we improve the TAP test to trigger this
too? To show the current code (in master) misses this?

Grigory, Andrey, Heikki, any opinions on the tweaks?


regards

-- 
Tomas Vondra

Attachment

pgsql-hackers by date:

Previous
From: "Vitaly Davydov"
Date:
Subject: Re: Slot's restart_lsn may point to removed WAL segment after hard restart unexpectedly
Next
From: vignesh C
Date:
Subject: Re: Random subscription 021_twophase test failure on kestrel