Re: pg_upgrade and frozen xids - Mailing list pgsql-admin

From Peter Geoghegan
Subject Re: pg_upgrade and frozen xids
Date
Msg-id CAH2-Wz=aNHWcZ3HMgofmvMDcUeLG9TVei1_ZCVNqROJAsapxYQ@mail.gmail.com
Whole thread Raw
In response to Re: pg_upgrade and frozen xids  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: pg_upgrade and frozen xids  (bricklen <bricklen@gmail.com>)
List pgsql-admin
On Wed, Mar 7, 2018 at 11:48 AM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> I wonder if this may be related to changes in collation algorithm.  If
> the indexes are all on text columns, I think you would be better served
> by reindexing them all instead of trying to treat this situation as a
> code bug.

I happen to know that bricklen already ran amcheck. There were errors,
but they were not consistent with a collation issue. Rather, it looked
like something was up with the storage layer -- the sibling links of a
pair of pages were not in mutual agreement.

Even if that wasn't something that I knew already, I still would not
suspect opclass misbehavior of any variety. VACUUM doesn't care about
the ordering of items on the page in the case of nbtree. And, it
performs a physical order scan there (albeit with some extra trickery
to prevent races due to concurrent splits). Index tuples that could
end up being unreachable to index scans due to opclass misbehavior
should remain reachable to VACUUM.

-- 
Peter Geoghegan


pgsql-admin by date:

Previous
From: Alvaro Herrera
Date:
Subject: Re: pg_upgrade and frozen xids
Next
From: Peter Geoghegan
Date:
Subject: Re: pg_upgrade and frozen xids