Three years ago we successfully migrated our application from Oracle DBMS to vanilla PostgreSQL. After that we faced with "childhood" diseases of our application on the new DBMS, which were successfully cured, and some "chronic diseases", which took much longer to deal with. One of the most memorable problems was the problem of DB performance degradation. The source of this problems was insufficient vacuuming of our database. The experience of understanding and solving this problem is offered to your attention in the form of practical recommendations to prevent DB tables and indices bloat and setting up PostgreSQL VACUUM/autovacuum parameters.