What is the difference between EXPLAIN and EXPLAIN ANALYZE? What happens if you run the same query with EXPLAIN ANALYZE twice in a row?

EXPLAIN shows the execution plan of an SQL query, that is, how the DBMS intends to obtain the result (indexes used, join order, table scan methods, etc.). This is a static analysis without actually executing the query.

EXPLAIN ANALYZE executes the query and additionally outputs statistics on the execution time of each plan step, the number of processed rows, and other metrics. This helps understand how well the plan matches the actual behavior.

If you run EXPLAIN ANALYZE twice in a row, the second run may show slightly different results due to data caching and plan caching in the DBMS. For example, data might already be in memory, speeding up execution, or statistics might change if data was updated between runs.