Re: First-draft release notes for next week's releases - Mailing list pgsql-hackers

On 2014-03-17 14:29:56 -0400, Tom Lane wrote:
> Andres Freund <andres@2ndquadrant.com> writes:
> > To me that looks sufficient to trigger the bug, because we're issuing a
> > wal record about the row that was passed to heap_lock_update(), not the
> > latest one in the ctid chain. When replaying that record, it will reset
> > the t_ctid field, thus breaking the chain.
> 
> [ scratches head ... ]  If that's what's happening, isn't it a bug in
> itself?  Surely the WAL record ought to point at the tuple that was
> locked.

There's a separate XLOG_HEAP2_LOCK_UPDATED record, for every later tuple
version, emitted by heap_lock_updated_tuple_rec(). This really is mind
bendingly complex :(.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services