Re: Why is my entire database getting locked for a slow select query?

[Shawn Taylor]

All inserts/updates prune any cached queries. From the manual:

Quote

If a table changes, all cached queries that use the table become invalid and are removed from the cache. This includes queries that use MERGE tables that map to the changed table. A table can be changed by many types of statements, such as INSERT, UPDATE, DELETE, TRUNCATE TABLE, ALTER TABLE, DROP TABLE, or DROP DATABASE.

http://dev.mysql.com/doc/refman/5.1/en/query-cache-operation.html

Shawn