EXPLAIN vs EXPLAIN ANALYZE

February 5, 2026

I ran into this while debugging a slow SQL query.

When debugging a slow query, we can use these two:

explain: shows how the database plans to execute the query (estimated cost, rows, indexes used, join strategy, etc.)

EXPLAIN query plan output

explain analyze: actually runs the query and shows actual execution metrics (actual time taken, rows, loops), so it’s usually more accurate.

EXPLAIN ANALYZE query plan output

In general, explain analyze shouldn’t be run on data-modifying statements (create table, alter, update, insert, drop, delete, truncate) unless the intention is to modify data.

Also, if a query is extremely expensive, explain analyze can add unnecessary load because it’s a real run.

Best practice would. be to:

Start with explain
If the plan / cost estimates differ than what we expected then run explain analyze.