How is pgsql explain used?

“Explain” is a command used in PostgreSQL to analyze query plans. By using the “explain” command, you can see how PostgreSQL performs a query, including the query plan, index usage, and data access methods.

The basic syntax for using the “explain” command is as follows:

EXPLAIN [SELECT 查询语句]

For example, you can use the following command to view the query plan:

EXPLAIN SELECT * FROM users WHERE age > 18;

The output of the “explain” command can help optimize query performance by adjusting the query statement, adding indexes, or redesigning table structures based on the output results.