How do I Improve Drupal 7 Forum Performance? I am working on a website that has 60k+ forum topics and it is extremelly slow. The problem is that the core forum module uses the following query

SELECT ncs.last_comment_timestamp AS last_comment_timestamp
, ncs.last_comment_uid AS last_comment_uid
, CASE ncs.last_comment_uid WHEN 0 THEN ncs.last_comment_name ELSE u2.name END AS last_comment_name FROM node n
INNER JOIN users u1 ON n.uid = u1.uid
INNER JOIN forum f ON n.vid = f.vid AND f.tid = '22'
INNER JOIN node_comment_statistics ncs ON n.nid = ncs.nid
INNER JOIN users u2 ON ncs.last_comment_uid = u2.uid WHERE  (n.status = '1') ORDER BY last_comment_timestamp DESC LIMIT 1 OFFSET 0


I saw that this query was the problem because after running the top command I saw that mysql was consuming 150%+ CPU so I ran a show full processlist that showed that the query above was always in the following state

Copying to tmp table    SELECT ncs.last_comment_timestamp AS last_comment_timestamp, ncs.last_comment_uid AS last_comment_uid, CASE ncs.last_comment_uid WHEN 0 THEN ncs.last_comment_name ELSE u2.name END AS last_comment_name\nFROM \nnode n\nINNER JOIN users u1 ON n.uid = u1.uid\nINNER JOIN forum f ON n.vid = f.vid AND f.tid = '22'\nINNER JOIN node_comment_statistics ncs ON n.nid = ncs.nid\nINNER JOIN users u2 ON ncs.last_comment_uid = u2.uid\nWHERE  (n.status = '1') \nORDER BY last_comment_timestamp DESC\nLIMIT 1 OFFSET 0


The result of the explain command is

id      select_type     table   type    possible_keys   key     key_len ref     rows    Extra
1       SIMPLE  f       ref     PRIMARY,tid     tid     4       const   30030   Using index; Using temporary; Using filesort
1       SIMPLE  n       eq_ref  PRIMARY,vid,node_status_type,uid        vid     4       drupal.f.vid    1       Using where
1       SIMPLE  ncs     eq_ref  PRIMARY,last_comment_uid        PRIMARY 4       drupal.n.nid    1
1       SIMPLE  u2      eq_ref  PRIMARY PRIMARY 4       drupal.ncs.last_comment_uid     1       Using where
1       SIMPLE  u1      eq_ref  PRIMARY PRIMARY 4       drupal.n.uid    1       Using where; Using index


Any ideas what to do to improve the performance here ?

Thanks
If you remove statistics then things should fly.   From my understanding drupal statistics does not scale well