Maintenance

The server maintains itself: SQLite checkpoints its WAL, and the server refreshes query statistics every hour (see SQLite). Two operations are left to you, both run by hand while the server is stopped.

Run both as the server’s user (see Install).

Giving back disk space#

SQLite reuses the space of deleted projections on its own, so the file doesn’t keep growing after a rebuild. To give that space back to the operating system, run a VACUUM. The server never runs one itself.

1. Stop tamarackdb-server, at a time the application can be down, for example at the end of a rebuild.

2. Run the VACUUM:

   sudo -u tamarackdb sqlite3 /path/to/data/tamarackdb.sqlite 'VACUUM;'

3. Start tamarackdb-server again.

A VACUUM rewrites the whole file, events included, and needs free disk space about the size of the database while it runs.

Refreshing query statistics#

After a one-off bulk import, run a full ANALYZE the same way:

sudo -u tamarackdb sqlite3 /path/to/data/tamarackdb.sqlite 'ANALYZE;'

Why the server is stopped. Stopping it costs a few seconds, and keeps the server free of a long operation it would have to coordinate with reads in flight. A WAL file left behind by another user is also one the server can’t open.