title: Is `ALTER TABLE mytable REPLICA IDENTITY FULL;` a safe operation for a high volume postgres database?
body: <p>I am working with debezium and a Postgres database. The database contains several tables with TOAST (The Oversized-Attribute Storage Technique) columns. To handle unchanged Postgres TOAST column values, one approach is to set the <code>REPLICA IDENTITY</code> of a table to <code>FULL</code>. However, I am not sure if running <code>ALTER TABLE mytable REPLICA IDENTITY FULL</code> could cause downtime on the database or it will be a safe operation. The current value for <code>REPLICA IDENTITY</code> is <code>DEFAULT</code>.</p>