Re: Is anyone aware of data loss causing MultiXact bugs in 9.3.2? - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Is anyone aware of data loss causing MultiXact bugs in 9.3.2?
Date
Msg-id CAM3SWZQ2vpLmzYscV32m=VY7W5qEsUUB26kvOAEcLj6RrRhLbw@mail.gmail.com
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In response to Re: Is anyone aware of data loss causing MultiXact bugs in 9.3.2?  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Is anyone aware of data loss causing MultiXact bugs in 9.3.2?  (Andres Freund <andres@2ndquadrant.com>)
List pgsql-hackers
On Tue, Feb 18, 2014 at 5:50 PM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> Peter Geoghegan wrote:
>> I've had multiple complaints of apparent data loss on 9.3.2 customer
>> databases. There are 2 total, both complaints from the past week, one
>> of which I was able to confirm. The customer's complaint is that
>> certain rows are either visible or invisible, depending on whether an
>> index scan is used or a sequential scan (I confirmed this with an
>> EXPLAIN ANALYZE).
>
> The multixact bugs would cause tuples to be hidden at the heap level.
> If the tuples are visible in a seqscan, then these are more likely to be
> related to index problems, not multixact problem.

I guess I wasn't clear enough here: The row in question was visible
with a sequential scans but *not* with an index scan. So you have it
backwards here (understandably).


-- 
Peter Geoghegan



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