RE: Handling large files with Emacs

["Ludwig, Mark" <ludwig.mark@siemens.com>]

> From: Tom
> Sent: Wednesday, October 24, 2012 2:09 PM
> To: help-gnu-emacs@gnu.org
> Subject: Re: Handling large files with Emacs
> 
> Eli Zaretskii <eliz <at> gnu.org> writes:
> > >
> > > BTW, why is it obsolete? Does it mean it's unnecessary and the
> > > size of the buffer should not be a problem?
> >
> > Yes.
> >
> 
> My other tip is long lines cause problems. SQL dumps have usually
> really long lines (the one below has lines with 1 million characters).
> 
> Here's as a testcase a dump from Wikipedia which is a 16MB download
> and it extracts to a 64MB sql file:
> 
> http://dumps.wikimedia.org/enwiki/20110901/enwiki-20110901-
> category.sql.gz
> 
> If I extract it, open it in emacs and try to scroll in the file here
> and there then emacs freezes for a minute or longer.
> 
> Actually with the above file I had to kill emacs, because it did
> not respond to anything after I did some random scrolling in the
> file, jumping to the end and then scrolling backwards, etc.
> 
> I tried it with -Q (emacs 24.1.1 on Windows).

Sure, I reported this as bug 9589 (http://debbugs.gnu.org/cgi/bugreport.cgi?bug=9589) against 23.1 on Windows.  You may wish to look at the bug report for the partial information I determined about which commands are fast and which are slow with very long lines.

Cheers,
Mark