Re: Dead rows not getting removed during vacuum - Mailing list pgsql-general

Granthana Biswas <granthana@zedo.com> writes:
> Version is PostgreSQL 9.1.4.

You do realize you're missing almost two years' worth of bug fixes?
The current release in that branch is 9.1.13, and a quick look through
the git history shows quite a number of replication-related fixes.

One that seems particularly notable in this connection is:

    commit 16222f32ed56d3ebc4136133662d932299188955
    Author: Simon Riggs <simon@2ndQuadrant.com>
    Date:   Thu Jun 7 19:24:47 2012 +0100

    Wake WALSender to reduce data loss at failover for async commit.
    WALSender now woken up after each background flush by WALwriter, avoiding
    multi-second replication delay for an all-async commit workload.
    Replication delay reduced from 7s with default settings to 200ms, allowing
    significantly reduced data loss at failover.

    Andres Freund and Simon Riggs

You wouldn't happen to be running with synchronous_commit off, would you?

Whether this is the explanation for your problem or not, it's really
irresponsible to still be running 9.1.4 at this point.  There are several
known data-loss-inducing bugs in it that will eat your data sooner or later.

                        regards, tom lane