parse_wal_dump

This is a simple Python script that takes the output of pg_waldump on standard input, parses it, and inserts records into a database with a subset of the information that is in the WAL file. It only parses and inserts records that can be attributed to a specific relation; other information is rejected.

It takes a single argument, which is a connection string to the databse to which to insert the data. If the table to hold the parsed data does not exist, it creates it; the schema is:

    CREATE TABLE IF NOT EXISTS wal_usage(
        lsn text primary key,
        rmgr text,
        len_rec int,
        len_tot int,
        tablespace int,
        database int,
        relation int

The main purpose of this script is to analyze WAL information to get an idea of how much changes to particular relations are contributing to the WAL volume.

Requirements

It requires the psycopg2 Python PostgreSQL interface library, available from:

https://www.psycopg.org

It can be installed using pip:

pip install psycopg2

It has been tested on Python 3.8.