WAL that is transferred by Streaming Replication can be compressed. This reduces the amount of data transferred for streaming replication and reduces the network load. This function can be used to increase throughput in cases where the network load is high due to Database aggregation, etc., or in environments where the network transfer speed is slow such as disaster prevention environments.

Using zEnterprise Data Compression(zEDC) for compression / decompression speeds up compression / decompression. Therefore, performance can be stabilized using zEDC.