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Concepts

Change data capture​

Change data capture (CDC) refers to the process of identifying and capturing changes made to data in a database and then delivering those changes in real-time to a downstream process or system.

Logical replication​

Logical replication is a method of replicating data objects and their changes based on their replication identity (usually a primary key). You can read more about logical replication and how it pertains to your database in Postgres' documentation here.

  1. Create a logical replication slot:

    SELECT pg_create_logical_replication_slot('$REPLICATION_SLOT_NAME', 'pgoutput');

    Learn more here.

  2. View your logical replication slots:

    SELECT slot_name, slot_type FROM pg_replication_slots WHERE slot_type = 'logical';

Write-ahead log​

A write-ahead log (WAL) is a standard way of ensuring data integrity by only allowing updates to the data in a database after a log has been written to permanent storage describing the change to take place.

This enhances data integrity because all changes to a database are recorded in these log files. In the event of a database crash, the database is recoverable using those logs and can even be recovered to a specific point in time.