After taking a look at transaction log archiving and PITR, we can focus our attention on one of the most widely used features in the PostgreSQL world today: streaming replication. The idea behind streaming replication is simple. After an initial base backup, the secondary can connect to the master and fetch a transaction log in real time and apply it. Transaction log replay is not a single operation anymore, but rather a continuous process that is supposed to keep running as long as the cluster exists.