Does anybody understand what autovacuum means meaning of databases?

Specific to PostgreSQL this means:

PostgreSQL's VACUUM command needs to run regularly for many reasons:

1.To recuperate or reuse disk space occupied by up-to-date or erased rows.

2.To update data statistics utilized by the PostgreSQL query planner.

3.To safeguard against lack of early data because of transaction ID wraparound.

On The Internet Application Engine this refers back to the Indexes (you vacuum a catalog, meaning you take it off).

On Postgre it describes cleaning up the database table (garbage collection and optimisation).

An autovacuum daemon waits until you will find no transactions after which dives directly into carry out the vacuum operation.

In postgres the AUTOVACUUM describes regular maintenance tasks:

  • To recuperate disk space occupied by up-to-date or erased rows.
  • To update data statistics utilized by the PostgreSQL query planner.
  • To safeguard against lack of early data because of transaction ID wraparound.

See: http://www.postgresql.org/docs/8.1/static/maintenance.html