Re: DISCARD ALL (Again) - Mailing list pgsql-hackers

From David Johnston
Subject Re: DISCARD ALL (Again)
Date
Msg-id CAKFQuwZ49gLV-OQVjS=-5d5v4tPWq=XQ9rgBHCGuuKeechhosg@mail.gmail.com
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In response to Re: DISCARD ALL (Again)  ("Joshua D. Drake" <jd@commandprompt.com>)
List pgsql-hackers


On Thursday, April 17, 2014, Joshua D. Drake <jd@commandprompt.com> wrote:

On 04/17/2014 07:07 PM, David G Johnston wrote:

    On 04/17/2014 05:24 PM, Tom Lane wrote:
     > On the whole I'm not sure this is something we ought to get into.
     > If you really need a fresh session, maybe you should start a
     > fresh session.


Isn't the whole point to avoid the reconnection overhead, especially for
connection poolers?  DISCARD ALL shouldn't cause any cleanup that
wouldn't otherwise occur when a session disconnects.  True global data
(not just session global) should be excluded.

The GD is global to the session only (Like temp tables).

Yes.  Tom's response makes it sound like the proposal is to throw away the entire language environment for the whole server (thus needing super user privilege) so I'm pointing out that what we are discussing is not that invasive.
 


A better wording of the promise would be: "discard all" leaves the
session in the same state it would be in if the underlying connection
were dropped and re-established.

Except that it doesn't.


But is this what you intend it to mean, by implementing these features, or are you thinking something different?

David J.
 

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