Horton

Re: synchronized snapshots

Thom Brown <thom@linux.com>

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From: Thom Brown <thom@linux.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Joachim Wieland <joe@mcknight.de>, Marko Tiikkaja <marko.tiikkaja@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-10-23T00:19:07Z
Lists: pgsql-hackers 
On 23 October 2011 00:25, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Joachim Wieland <joe@mcknight.de> writes:
>> [ synchronized snapshots patch ]
>
> Applied with, um, rather extensive editorialization.
>
> I'm not convinced that the SSI case is bulletproof yet, but it'll be
> easier to test with the code committed.

Can I ask why it doesn't return the same snapshot ID each time?
Surely it can't change since you can only export the snapshot of a
serializable or repeatable read transaction?  A "SELECT
count(pg_export_snapshot()) FROM generate_series(1,10000000);" would
quickly bork the pg_snapshots directory which any user can run.

-- 
Thom Brown
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