[Xapian-discuss] Xapian performance testing

[Kevin Duraj]

I have encountered the same issue having slow queries when term
contain dash characters.

I do not have solution except that I replaced the '-' with 'dash'
inside of the index.
Example: 'd-link', 's-video' as temporary solution: ' ddashlink', ' sdashvideo'

Perhaps we could address this slowness issue of dash characters in the
near future.

Kevin Duraj
http://myhealthcare.com


On Tue, Mar 18, 2008 at 1:26 AM, Arjen van der Meijden
<acmmailing at tweakers.net> wrote:
> On 5-11-2007 14:40, Olly Betts wrote:
>  > BTW, I have implemented the hoisting of the positional information
>  > checking part of NEAR and PHRASE, so that the "AND" inside can be
>  > merged with other AND and FILTER operations.  This gave a big
>  > performance boost to the slow queries (~50% saving in time just
>  > from this one change) and a good boost to the other queries (~25%
>  > saving from just this change).
>  >
>  > This optimisation and all the earlier ones are in 1.0.4, so once you
>  > upgrade to that, it would be interesting to see what the slow query log
>  > looks like with these new optimisations in place.
>
>  We finally found time to upgrade our 0.9.8 to 1.0.5 and reindex the
>  whole database. The results so far are quite good.
>  When taking the daily average of our forum search result page it went
>  down from about 0.55 seconds to about 0.38 seconds.
>  Looking at the log-files, the slow query log file (queries taking more
>  than 2 seconds) dramatically reduced in size. Prior to the update we had
>  3190 and 3112 lines in a week and now in the latest week it had only 863
>  lines.
>
>  The slowest queries seem to be the single-term phrases with a single
>  character attached to a common word like 'd-link', 's-video' and
>  variants on that with only a few additional terms. As expected, I don't
>  see any version numbers anymore in the slow query log.
>
>  Best regards,
>
>  Arjen van der Meijden
>  Tweakers.net
>
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