I personally think that you do not need a global cache.

this data is session data, and you should keep it in it. 10 thousands record of about 200 bytes each is 2Mb. If you are planning to serve hundreds of user per time, this is a viable solution.

iff you fear the memory will be growth too much (and you can't shorten the session timeout anymore), then you can use Tie::Cache but using as hash key a query id. every time a user issue a request, the data is stored in this cache with a unique query id, and the id is set on the session of the user. if the user request the same query id, then you'll use the cached one.

Oha