Android data storage issue

I have an app which stores data in a SQLite database, when the app is just installed it uses 8kb of data and when I start inserting data obviously the 开发者_高级运维size increases. The weird thing is when I start cleaning my database tables, I empty completely the database but I will never recover the first 8kb of data but much more, in some cases more than 100kb, where this data come from?

A database is not like a filesystem, so when you delete data from a database, you do not recover the space you previously used. The database driver will tend to prefer to keep the old allocated space.

You can compact your database, which will recover this space by manually executing the SQLite VACUUM command.

It may be possible to enable auto_vacuum mode, but this needs to be done before database creation.