Hi!
On Dec 04, tk wrote:
> Hello,
>
> Thanks for the response.
> There is one thing that is not clear however.
>
> Regardless of whether or not I perform the fulltext
> search with or without the SQL_CALC_FOUND_ROWS
> keyword, the results that I get are exactly the same.
>
> Also, the notion of stopping after the limit is
> reached cannot apply in the fulltext search or
> otherwise we would only get the first 10 matches but
> not the first 10 "most relevant" matches. This leads
> me to believe that the fulltext search must be looking
> at all the rows in both cases since it otherwise would
> not find the same first 10 most relevant records.
> Hence the question why there should be a difference in
> time.
The difference is that you only need to read 10 rows from the disk
without SQL_CALC_FOUND_ROWS.
With SQL_CALC_FOUND_ROWS MySQL goes on and reads all rows, it takes
time.
Finding relevant rows and sorting is based on index only, row data are
not read.
Regards,
Sergei
--
__ ___ ___ ____ __
/ |/ /_ __/ __/ __ \/ / Sergei Golubchik <serg@stripped>
/ /|_/ / // /\ \/ /_/ / /__ MySQL AB, Senior Software Developer
/_/ /_/\_, /___/\___\_\___/ Osnabrueck, Germany
<___/ www.mysql.com
