Postgres uses an internal table called ‘pg_statistic’ to keep track of some metadata on all tables in the DB. Postgres’s Planner uses these statistics when estimating the cost of operations, which, if out of date, can cause the Planner to pick a suboptimal plan for our query. To trigger an update of ‘pg_statistic’ manually for a table, we can run ‘ANALYZE’ on it, helping the Planner estimate costs better and speeding up queries dramatically (in some cases).
