We have an application database (which includes a table for users). Here's the setup: 1Kbyte of data per user that's based on counting fields * typelength and about 100 things of the same size that belongs to a user (about 0.5 Kbyte). This leads to around 51 Kbytes of data per user. Now, we're using MySQL and we were told to cover the index tables, which would double the size per user (102 Kbytes). Is that a good estimate? Are there any other factors to consider for MySQL?