Item14037: PageCache needs an index on the to_topic field.
Current State: Closed
Released In: 2.1.1
Target Release: patch
Very long topic save times on foswiki.org was traced to very long cache update times.
- foswiki_cache_pages: 55,457 rows
- foswiki_cache_deps: 7,050,189 rows
The only index on the deps table is:
KEY `foswiki_cache_deps_index` (`from_topic`,`to_topic`)
However on topic update, the deps table is joined with the pages table, =where to_topic='the saved topic'; And is referenced again, to delete all the deps rows for that to_topic.
Adding a simple index on to_topic reduced a simple count(*) for a unique to_topic from 16 seconds to sub-second. This will have similar impact on the join and delete operation. Index has been added to foswiki.org, but we need to create this index by default.
- 03 Apr 2016
This index should be created by
Which patch did you apply to them?
- 04 Apr 2016