Sqlite Vacuum

Today I learned how to VACUUM a sqlite database and cut its size in about half. It's a database that I have had running for quite awhile and has some decent traffic on it.

Why is it important to do a VACUUM? In short its becuase the file system gets fragmented with as data is updated. On delete the files are removed from the database and marked as available for reuse in the filesystem, but the space is not reclaimed.

To VACUUM a database, run the following sql command. You can do it right form the sqlite shell by running sqlite3.

You will need about double the current size of the database as free space to do the VACUUM, you need space for a full copy, journaling or write ahead logs, and the existing database.


The docs are fantastic for vacuum.