Conference Schedule - PGCon 2022

Logical Change Records, the logical WALs

Date: 2022-05-26
Time: 10:00 - 10:45
Room: Stream 2
Level: Intermediate

Unlike physical replication, which does not understand a "bit" of WAL record, Logical Replication interpretes WAL records and sends changes to the replica in a "logical" form. The process of converting a WAL record into a Logical Change Record (LCR in short) is time and resource consuming. Each WAL sender, publishing from a given set of publications, repeats this process producing same LCR stream for a given WAL stream. LCRs when saved to the disk can be used by many WAL senders, thus reducing CPU and memory consumption.

In this presentation, we will discuss the everything related to LCRs and how it helps in BDR to support hundreds of WAL senders.


Ashutosh Bapat