H2 Database – Explain
EXPLAIN command displays the execution plan for a statement. When we execute a statement using EXPLAIN ANALYZE command, the query plan will include the actual row scan count for each table.
Syntax
Following is the generic syntax of the EXPLAIN command.
EXPLAIN { [ PLAN FOR ] | ANALYZE } { select | insert | update | delete | merge}
Along with this syntax we can use select, insert, delete, and merge.
Example
This example explains the query plan details of the customer with ID 1.
EXPLAIN SELECT * FROM CUSTOMER WHERE ID = 1;
The above command produces the following output −