crabiet

This is a very simple plugin which just shows your DataBase size under the header of the admin control panel. Usefull for those who have database size limited by their host. 
Database size appears in green if under 4 MBytes by default, else in red if over this value.

DATABASE SIZE WORPRESS PLUGIN

sdkester

The Latency Tracker plugin counts the number of database calls and speed of your site, tracks it over time, and gives you some statistics about the performance of your site.

Latency Tracker

Keeps track of the queries, loading time, and memory usage of your Wordpress site.

DATABASE SIZE WORPRESS PLUGIN vs Latency Tracker