On Sun, Nov 08, 2009 at 05:00:53PM +0100, Andres Freund wrote:
> On Sunday 01 November 2009 16:19:43 Andres Freund wrote:
> > While playing around/evaluating tsearch I notices that to_tsvector is
> > obscenely slow for some files. After some profiling I found that this is
> > due using a seperate TSParser in p_ishost/p_isURLPath in wparser_def.c. If
> > a multibyte encoding is in use TParserInit copies the whole remaining
> > input and converts it to wchar_t or pg_wchar - for every email or protocol
> > prefixed url in the the document. Which obviously is bad.
> >
> > I solved the issue by having a seperate TParserCopyInit/TParserCopyClose
> > which reuses the the already converted strings of the original TParser -
> > only at different offsets.
> >
> > Another approach would be to get rid of the separate parser invocations -
> > requiring a bunch of additional states. This seemed more complex to me, so
> > I wanted to get some feedback first.
> >
> > Without patch:
> > andres=# SELECT to_tsvector('english', document) FROM document WHERE
> > filename = '/usr/share/doc/libdrm-nouveau1/changelog';
> >
> >
??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
> > ????????????????????????????????????????????????????????????????????????????????? ...
> > (1 row)
> >
> > Time: 5835.676 ms
> >
> > With patch:
> > andres=# SELECT to_tsvector('english', document) FROM document WHERE
> > filename = '/usr/share/doc/libdrm-nouveau1/changelog';
> >
> >
??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
> > ????????????????????????????????????????????????????????????????????????????????? ...
> > (1 row)
> >
> > Time: 395.341 ms
> >
> > Ill cleanup the patch if it seems like a sensible solution...
> As nobody commented here is a corrected (stupid thinko) and cleaned up
> version. Anyone cares to comment whether I am the only one thinking this is an
> issue?
>
> Andres
+1
As a user of tsearch, I can certainly appreciate to speed-up in parsing --
more CPU for everyone else.
Regards,
Ken
