My knowledge of MySQL is pathetic to be honest. It’s definitely something I should familiarize myself with. Could you explain that to me so a pickle could understand it? :/
Cyberpower678 English Wikipedia Account Creation Team Mailing List Moderator > On Nov 12, 2014, at 10:45, Brad Jorsch (Anomie) <[email protected]> wrote: > > On Sun, Nov 9, 2014 at 1:25 PM, Maximilian Doerr <[email protected] > <mailto:[email protected]>> wrote: > [1] => Array > ( > [time] => 18.95 > [query] => SELECT rev_timestamp, > page_title, page_namespace FROM revision_userindex JOIN page ON page_id = > rev_page WHERE (`rev_user` = '14836860') AND `rev_timestamp` > 1 ORDER BY > rev_timestamp ASC LIMIT 0,2688354; > [result] => succeeded > ) > > The proper indexes seem to be in place on the underlying tables, based on a > "SHOW CREATE TABLE enwiki.revision" which is the backing for both > enwiki_p.revision and enwiki_p.revision_usertext. > > And when I try the "SHOW EXPLAIN" trick to get an explanation, it claims it's > using an index: > > +------+-------------+----------+--------+---------------------------------------+----------------+---------+--------------------------+-------+-----------------------------+ > | id | select_type | table | type | possible_keys > | key | key_len | ref | rows | Extra > | > +------+-------------+----------+--------+---------------------------------------+----------------+---------+--------------------------+-------+-----------------------------+ > | 1 | SIMPLE | revision | ref | > PRIMARY,page_timestamp,user_timestamp | user_timestamp | 4 | const > | 29186 | Using where; Using filesort | > | 1 | SIMPLE | page | eq_ref | PRIMARY > | PRIMARY | 4 | enwiki.revision.rev_page | 1 | > | > +------+-------------+----------+--------+---------------------------------------+----------------+---------+--------------------------+-------+-----------------------------+ > > The filesort there seems odd to me, and can lead to slow queries. > > Or it could just be that it's having to load 13996 rows from the revision > table and 13996 rows from the page table and the disk access is slow. > _______________________________________________ > Labs-l mailing list > [email protected] > https://lists.wikimedia.org/mailman/listinfo/labs-l
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