Slow query pulled from viewing the processlist in mysql:

SELECT DISTINCT mantis_bug_table.id AS id FROM mantis_project_table, mantis_bug_table LEFT JOIN mantis_custom_field_string_table mantis_custom_field_string_table_3 ON mantis_custom_field_string_table_3.bug_id = mantis_bug_table.id LEFT JOIN mantis_custom_field_string_table mantis_custom_field_string_table_2 ON mantis_custom_field_string_table_2.bug_id = mantis_bug_table.id WHERE mantis_project_table.enabled = 1 AND mantis_project_table.id = mantis_bug_table.project_id AND ( mantis_bug_table.project_id=2 ) AND (mantis_bug_table.view_state='10' OR mantis_bug_table.reporter_id='75')

The interesting thing is that the custom fields have no constraints set. I think they could be left out of the query. I fixed the slow queries on my setup by adding an index. I am running a recent checkout from cvs HEAD.

Added following index and the query returns in less 0.1 secs vs. ~60 secs on my system.

"alter table mantis_custom_field_string_table add index bug_id_idx (bug_id);"

The primary key does include bug_id, but it is the second field in the index therefore mysql does not use it for the query.