pg_wsl

PostgreSQL extension to write from primary to standby log

Compiling

This module can be built using the standard PGXS infrastructure. For this to work, the pg_config program must be available in your $PATH:

git clone https://github.com/pierreforstmann/pg_wsl.git
cd pg_wsl
make
make install

This extension can only work with PostgreSQL 15.

Usage

Install pg_wsl on primary and standby node using above mentionned steps.

Add in primary instance and standby instance:

shared_preload_libraries='pg_wsl'

Restart primary and standby instances with:

pg_ctl stop
pg_ctl start

Create extension pg_wsl in primary instance:

create extension pg_wsl;

Connect to primary instance to run:

psql -c "select pg_wsl_rmgr('Hello from primary');"

Standby log should display something similar to:

2023-03-19 16:49:57.512 CET [50550] LOG:  pg_wsl_redo: message Hello from primary
2023-03-19 16:49:57.512 CET [50550] CONTEXT:  WAL redo at 0/110258A8 for pg_wsl/XLOG_WSL_RMGR: message Hello from primary (19 bytes)