Re: snapshot too old, configured by time - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: snapshot too old, configured by time
Date
Msg-id 20160423030425.GE5939@momjian.us
Whole thread Raw
In response to Re: snapshot too old, configured by time  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: snapshot too old, configured by time  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
On Tue, Apr 19, 2016 at 07:38:04AM -0400, Robert Haas wrote:
> 2. Without this feature, you can kill sessions or transactions to
> control bloat, but this feature is properly thought of as a way to
> avoid bloat *without* killing sessions or transactions.  You can let
> the session live, without having it generate bloat, just so long as it
> doesn't try to touch any data that has been recently modified.  We
> have no other feature in PostgreSQL that does something like that.

I kind of agreed with Tom about just aborting transactions that held
snapshots for too long, and liked the idea this could be set per
session, but the idea that we abort only if a backend actually touches
the old data is very nice.  I can see why the patch author worked hard
to do that.

How does/did Oracle handle this?  I assume we can't find a way to set
this per session, right?

--  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 +



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