What is the purpose and feature of the “limit” clause in PostgreSQL?

LIMIT in PostgreSQL is a keyword used to restrict the number of rows returned in a query result set. By using the LIMIT keyword in a SELECT query statement, you can specify the limit of rows to be returned, thus reducing the size of the query result set.

The characteristics of the LIMIT keyword include:

1. You can specify a limit on the number of rows returned to control the size of the query result set.
2. It can be used in conjunction with ORDER BY to return rows in a specific order in the results.
3. It can be used together with the OFFSET keyword to specify the starting position of rows to be returned from the query result set.
4. You can use LIMIT ALL to return all matching rows without limiting the number of rows returned.
5. It can be used for pagination by limiting the number of rows returned and the offset in each query to achieve pagination effect.