Horton

Re: BUG #16454: Mixed isolation levels inside transactions

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: lalbin@scharp.org, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Date: 2020-05-21T01:56:47Z
Lists: pgsql-bugs 
On Thu, May 21, 2020 at 12:59 PM PG Bug reporting form
<noreply@postgresql.org> wrote:
> I am seeing mixed/hybrid Isolation Levels when setting the isolation level
> to SERIALIZABLE READ ONLY DEFERRABLE, this also happens with REPEATABLE READ
> READ ONLY. The user tables sees only the data committed before the
> transaction begins but the system tables sees data committed by other
> transactions after the transaction begins. This means in my example the user
> tables are Serializable Isolation Level and the system tables are Read
> Committed Isolation Level.

That is expected behaviour.  Perhaps we're missing a note about it in
the manual?

Commits

  1. Doc: Add references for SI and SSI.