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Message-ID: <7c33d060608041036k59056658o5acd68df36d0bbb6@mail.gmail.com>
Date: Sat, 5 Aug 2006 00:36:42 +0700
From: "David Garamond" <davidgaramond@gmail.com>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Subject: Re: autoupdating mtime column
Cc: pgsql-sql@postgresql.org
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On 8/4/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> If you are really intent on having a way to suppress the mtime update
> you could dedicate an additional field to the purpose, eg
>
> UPDATE t SET foo=..., bar=..., keepmtime = true ...
>
> and in the trigger something like
>
>         if new.keepmtime then
>                 new.keepmtime = false;
>         else
>                 new.mtime = now();
>
> As long as nothing else ever touches keepmtime this would work.
> Personally I'm dubious that it's worth the trouble


Yeah, it's too expensive an overhead just for the sake of a slightly shorter
UPDATE statement.

--- do you
> have a real use-case for suppressing mtime updates?
>

Syncing tables between databases (a la "rsync --times"). Btw, I'm
considering temporarily disabling the update_times() trigger when sync-ing.

Thanks,
--
dave

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On 8/4/06, <b class="gmail_sendername">Tom Lane</b> &lt;<a href="mailto:tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>&gt; wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
If you are really intent on having a way to suppress the mtime update<br>you could dedicate an additional field to the purpose, eg<br><br>UPDATE t SET foo=..., bar=..., keepmtime = true ...<br><br>and in the trigger something like
<br><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if new.keepmtime then<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;new.keepmtime = false;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;new.mtime = now();<br><br>As long as nothing else ever touches keepmtime this would work.<br>Personally I'm dubious that it's worth the trouble
</blockquote><div><br>Yeah, it's too expensive an overhead just for the sake of a slightly shorter UPDATE statement.&nbsp;</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
 --- do you<br>have a real use-case for suppressing mtime updates?<br></blockquote></div><br>Syncing tables between databases (a la &quot;rsync --times&quot;). Btw, I'm considering temporarily disabling the update_times() trigger when sync-ing.
<br><br>Thanks,<br>--<br>dave<br>

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