Re: [HACKERS] - WIP Patch Updatable Cursor - Mailing list pgsql-patches

From John Bartlett
Subject Re: [HACKERS] - WIP Patch Updatable Cursor
Date
Msg-id !~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAA/w1P36NVXkuUGCDGiycCfMKAAAAQAAAADPOlSx7DTEirLCUebrOeSAEAAAAA@fast.fujitsu.com.au
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In response to Re: [HACKERS] - WIP Patch Updatable Cursor  (Gavin Sherry <swm@alcove.com.au>)
List pgsql-patches
Hi Gavin,

Thanks for your comments. 

I shall set up the ctids list to be stored in memory initially and dump to a
temp file if needed.

Regards,
John Bartlett

-----Original Message-----
From: pgsql-patches-owner@postgresql.org
[mailto:pgsql-patches-owner@postgresql.org] On Behalf Of Gavin Sherry
Sent: Wednesday, 28 February 2007 3:23 PM
To: John Bartlett
Cc: pgsql-hackers@postgresql.org; pgsql-patches@postgresql.org; 'Heikki
Linnakangas'
Subject: Re: [HACKERS] [PATCHES] - WIP Patch Updatable Cursor

On Wed, 28 Feb 2007, John Bartlett wrote:

> Hi,
>
> A list of ctids is stored in the file.

I would have thought these would be stored in memory. If the set got
large, you'd use a temporary file the way other systems which overflow to
disk do?

>
> The file is used to store the ctids during an updatable cursor
transaction.
>
> It is set up as a permanent file as it has a potential lifetime of
> preserving data between crashes of the backend. Temporary files tend to be
> used for data that is defined within a single command. In this case the
file
> needs to exist within a transaction and across backend processes.

It does not. Cursors are implicitly closed when a session is closed. A
backend crash or system restart closes all open sessions.

>
> The file gram.y has been corrected in my version.
>
> The files ctidListStore.c and ctidListStore.h were pasted into the patch
> file, as the diff -N command produced a file of several hundred thousand
> lines.

Edit the file with a text editor. If you know which files should be
excluded (like tags files), use diff --exclude=<pattern>.

Thanks,

Gavin

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