Hi there
we're using memcache in several of our Rails applications. Now I was wondering: Is there a way to get a list of all objects stored in memcache including the amount of data each value occupies?
E.g.:
key | memory(Bytes) | %
-----------------------------------
foo_key | 15013 | 0.3
bar_key | 2201 | 0.05
Couldn't find anything in the docs...
Thanks
Matt
No, we have no intention of supporting such functionality.
Currently, all memcached operations are O(1) (that includes flush). Having an operation that gives you a list of keys can't satisfy that constraint. It would require locks that will be held for the duration of the request, and give you information that may be inaccurate at the very moment you see it.
It's the kind of thing people ask for frequently, but nobody has ever presented a use case where a) they needed it and b) they were using memcached in a way that wasn't harmful to their environment.
Think Heisenberg uncertainty principal meets ephemeral storage.
No. It's a cache, not a database. If you have to do things like that, you'll be better off with something else than Memcached.
See the FAQ for further information
Memcached has never acted much like a database, being able to query for a specified set of rows and such.
If you want a memory based database, you could go with MySQL and create MEMORY tables. They function purely in memory, bypassing the slow disk-based accesses to give you higher performance.