Implementing Online Schema Changes in PostgreSQL 15: A Practical Guide Using pg_repack

Implementing Online Schema Changes in PostgreSQL 15: A Practical Guide Using pg_repack

To implement an online schema change in PostgreSQL 15, tools like pg_repack or logical replication can be used. Here's a real-life example using pg_repack:

Scenario: You need to add an index to a large, heavily used table customer_data.

  1. Install pg_repack:
    • Install the pg_repack extension on your PostgreSQL server.
  2. Run pg_repack:

    • Execute pg_repack to add the index while allowing normal operations on the table:

      pg_repack -d mydatabase --table=customer_data --create-index="CREATE INDEX idx_customer_name ON customer_data(name)"

In this example, pg_repack reorganizes the customer_data table to add the idx_customer_name index, minimizing locks and allowing the table to remain online and accessible during the process.