Re: Incorrect visibility test function assigned to snapshot - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Incorrect visibility test function assigned to snapshot
Date
Msg-id 20180623151856.GG21575@momjian.us
Whole thread Raw
In response to Re: Incorrect visibility test function assigned to snapshot  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Incorrect visibility test function assigned to snapshot
List pgsql-hackers
On Wed, May 30, 2018 at 09:28:54AM -0400, Alvaro Herrera wrote:
> On 2018-May-30, Antonin Houska wrote:
> 
> > In the header comment, SnapBuildInitialSnapshot() claims to set
> > snapshot->satisfies to the HeapTupleSatisfiesMVCC test function, and indeed it
> > converts the "xid" array to match its semantics (i.e. the xid items eventually
> > represent running transactions as opposed to the committed ones). However the
> > test function remains HeapTupleSatisfiesHistoricMVCC as set by
> > SnapBuildBuildSnapshot().
> 
> Interesting.  While this sounds like an oversight that should have
> horrible consequences, it's seems not to because the current callers
> don't seem to care about the ->satisfies function.  Are you able to come
> up with some scenario in which it causes an actual problem?

Uh, are we going to fix this anyway?  Seems we should.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +


pgsql-hackers by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: Supporting tls-server-end-point as SCRAM channel binding forOpenSSL 1.0.0 and 1.0.1
Next
From: Vik Fearing
Date:
Subject: Re: Adding Markodwn formatting to psql output