Query caching on table level

[eluser]Volder[/eluser]
this is the main problem which I'm facing.

The native DB cache class stores file for every cached queries, but in pages structure:

CodeIgniter places the result of EACH query into its own cache file. Sets of cache files are further organized into sub-folders corresponding to your controller functions. To be precise, the sub-folders are named identically to the first two segments of your URI (the controller class name and function name).

and following:

For example, let's say you have a blog that allows user commenting. Whenever a new comment is submitted you'll want to delete the cache files associated with the controller function that serves up your comments.

but imagine my comments queries are used in a bunch of controllers. And at the same time my controller which uses comments quiery - uses a lot of other quiries which are no how connected to comments - but I have to delete it.

What I would like - that caching would be organized on table level. So when I update Comments table - I want to clear cache only for queries which used this table.

Hope now the idea of what I need is more clear.
Actually, I was very surprised that this is not implemented natively in CI yet.