wishes for postgres plugins

[petere]

While upgrading from some older third-party postgres plugins to the ones included in munin 1.4, I noticed two small bits of functionality that I miss:

• A view like postgres_cache_ that shows the cache hit ratio in percent. This is occasionally more useful that seeing the absolute values.

• postgres_tuples_ separated into two views for read and write activity. Since the read activity often trumps the write activity by orders of magnitude, it is hard to see anything about the write activity on this view.

Maybe these could be added sometime.