Skip to main content

PostgreSQL Connector

A Macrometa connector that extracts data from or sends data to an existing Postgres database.


  • Macrometa account with admin permissions
  • A remotely accessible, running Postgres instance
  • The source from where the data is extracted for the target connector to consume, cannot be empty. It must have some data.

PostgreSQL Source

Read this section carefully before you set up your PostgresSQL source connector.

Log-Based Replication Requirements

This section explains what you need in order to use log-based replication with your PostgreSQL source.

Minimum Version

To avoid a critical PostgreSQL bug, your PostgreSQL database must have PostgreSQL versions 9.4.x or greater.

Master Instance Connection

Log-based replication only works when the integration connects to the master instance.

wal2json Plugin

You must install the wal2json plugin. The wal2json plugin outputs JSON objects for logical decoding, which the source connector then uses to perform log-based replication.

Steps for installing the plugin vary depending on your operating system. Instructions for each operating system type are in the wal2json's GitHub repository:

Update Postgres Config File

Locate the database configuration file (usually postgresql.conf) and define the parameters as follows:


For max_replication_slots and max_wal_senders, we recommend a value of 5. This should be sufficient unless you have a large number of read replicas connected to the master instance.

Restart your PostgreSQL service to ensure the changes take effect.

Existing Replication Slot

Log-based replication requires a dedicated logical replication slot. In PostgreSQL, a logical replication slot represents a stream of database changes that can then be replayed to a client in the order they were made on the original server. Each slot streams a sequence of changes from a single database.

Log in to the master instance as a superuser and using the wal2json plugin, create a logical replication slot:

FROM pg_create_logical_replication_slot('macrometa_<database_name>', 'wal2json');

You can pass this replication slot in the configuration parameter for LOG_BASED replication method.


Replication slots are specific to a given database in a cluster. If you want to connect multiple databases, whether in one integration or several, then you must create a replication slot for each database.

PostgresSQL Target

No additional notes.