[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: SQLite and callbacks

From: Stefan Sperling <stsp_at_elego.de>
Date: Tue, 8 Feb 2011 20:15:56 +0100

On Tue, Feb 08, 2011 at 06:02:28PM +0100, Branko Čibej wrote:
> On 08.02.2011 16:34, Bert Huijben wrote:
> > An even better solution would be that SQLite tries to do things completely in memory and only *creates* a tempfile when needed. (It seems it now creates the file anyway; but doesn't use it until needed. Introducing a heavy performance penalty on NTFS, but not on extXfs)
>
> You mentioned testing on journalled filesystems. Maybe you don't
> consider ext3 and ext4 to be journalled, but my tests were done on
> journalled HFS+ on Mac OS.
>
> Yes, creating a temporary file is moderately expensive. But in the
> approach I showed, you really only create one temporary table and/or
> database per WC operation, not 50 zillion.
>
> That said, I agree that a lot more testing and measuring needs to be
> done. And after all, a memory-backed temporary table is in the worst
> case backed by swap space.

All good points, yes.

Getting the queries right is much more important than worrying about
the temp_store pragma.
Received on 2011-02-08 20:16:42 CET

This is an archived mail posted to the Subversion Dev mailing list.