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

Search Discussions

  • John Bartlett at Mar 2, 2007 at 6:42 am
    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
    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

    ---------------------------(end of broadcast)---------------------------
    TIP 1: if posting/reading through Usenet, please send an appropriate
    subscribe-nomail command to majordomo@postgresql.org so that your
    message can get through to the mailing list cleanly

    This is an email from Fujitsu Australia Software Technology Pty Ltd, ABN 27 003 693 481. It is confidential to the ordinary user of the email address to which it was addressed and may contain copyright and/or legally privileged information. No one else may read, print, store, copy or forward all or any of it or its attachments. If you receive this email in error, please return to sender. Thank you.

    If you do not wish to receive commercial email messages from Fujitsu Australia Software Technology Pty Ltd, please email unsubscribe@fast.fujitsu.com.au

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
grouppgsql-hackers @
categoriespostgresql
postedFeb 28, '07 at 4:22a
activeMar 2, '07 at 6:42a
posts2
users2
websitepostgresql.org...
irc#postgresql

2 users in discussion

John Bartlett: 1 post Gavin Sherry: 1 post

People

Translate

site design / logo © 2021 Grokbase