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Thread: Synchronized Scan

Synchronized Scan

From
Jeff Davis
Date:
Here is the latest version of my patch that's revised according to my
discussions with Heikki and Simon:

Changes:
  * uses LWLocks when accessing shared memory
  * removes the "sync_seqscan_offset" feature
  * uses the relfilenode as a key rather than relation OID
  * fixes regression test failure
  * uses a simple LRU (that stays in fixed-size shared memory) to track
the locations of other concurrent scans

For the LRU I used a doubly-linked list, which isn't strictly necessary.
However, we may decide to use a hash table for the lookup, in which case
the extra pointers will be useful.

Regards,
    Jeff Davis
Attachment

Re: Synchronized Scan

From
Peter Eisentraut
Date:
Am Montag, 21. Mai 2007 00:01 schrieb Jeff Davis:
> Here is the latest version of my patch that's revised according to my
> discussions with Heikki and Simon:

This patch was apparently done against 8.2.4, but it doesn't apply to CVS
head.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

Re: Synchronized Scan

From
Jeff Davis
Date:
On Mon, 2007-05-21 at 16:03 +0200, Peter Eisentraut wrote:
> Am Montag, 21. Mai 2007 00:01 schrieb Jeff Davis:
> > Here is the latest version of my patch that's revised according to my
> > discussions with Heikki and Simon:
>
> This patch was apparently done against 8.2.4, but it doesn't apply to CVS
> head.
>

Thanks. Here's a version that applies cleanly to CVS head.

Regards,
    Jeff Davis
Attachment

Re: Synchronized Scan

From
Bruce Momjian
Date:
Your patch has been added to the PostgreSQL unapplied patches list at:

    http://momjian.postgresql.org/cgi-bin/pgpatches

It will be applied as soon as one of the PostgreSQL committers reviews
and approves it.

---------------------------------------------------------------------------


Jeff Davis wrote:
> On Mon, 2007-05-21 at 16:03 +0200, Peter Eisentraut wrote:
> > Am Montag, 21. Mai 2007 00:01 schrieb Jeff Davis:
> > > Here is the latest version of my patch that's revised according to my
> > > discussions with Heikki and Simon:
> >
> > This patch was apparently done against 8.2.4, but it doesn't apply to CVS
> > head.
> >
>
> Thanks. Here's a version that applies cleanly to CVS head.
>
> Regards,
>     Jeff Davis

[ Attachment, skipping... ]

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--
  Bruce Momjian  <bruce@momjian.us>          http://momjian.us
  EnterpriseDB                               http://www.enterprisedb.com

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