Re: [PATCH] cvsserver: avoid warning about active db handles

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jul 25, 2006, 14:53 UTC
Message-ID: <Pine.LNX.4.63.0607251649190.29667@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <44C6099A.5010205@catalyst.net.nz>

Hi,

[sorry for the delay... darn meetings]

On Wed, 26 Jul 2006, Martin Langhoff (CatalystIT) wrote:

Show 8 quoted lines

> Johannes Schindelin wrote:
> 
> > Turns out that DBD::SQLite does not favour preparing statements which 
> > are never executed. So, turn all 4 statements, which were prepared 
> > _always_, into methods, like the other 12 prepared statements.
> 
> Can you give me a reference for that "does not favour preparing 
> statements"?

The relevant bug entry is

	http://rt.cpan.org/Public/Bug/Display.html?id=17603

> I have some vague recollection of timing prepared/unprepared inserts and 
> getting a huge difference in performance.

Yes, preparing before executing is a wonderful thing. But you need to execute the prepared statements; otherwise it is a waste of resources (plus, it does not finalize with DBD::SQLite).

> Looking at the source of SQLite.pm doesn't clarify much -- 
> prepare_cached is actually implemented by DBI, the driver doesn't need 
> to implement it.

Yes. The culprit is in prepare().

Show 5 quoted lines

> > 	Now, the only warning left is the gzip one...
> 
> That's harder. I wonder whether using libgit's XS module we can now get 
> libgit to give us a gzipped file directly. I guess it only has 
> performance savings for unpacked repos.

I still have the problem on at least two of my boxes that Git.xs does not load. The next thing after looking into the gzip thing is to rewrite git-mv in C.

Ciao, Dscho