I have a 20 Tb database in PostgreSQL 9.2 and I have no idea how to efficiently create backups. It's a database that grows a little bit every day and on the 1 of each month it grows about 200 Gb.
I was thinking of doing a pg_dump, but it takes too much to do it every month, then I think about doing it one time, and then backup just the new or changed tables with copy, but I can't stop using the database in order to create the first dump, so I won't exactly know exactly which data does the backup contains.
How can I do an incremental backup without stop using the database?