Learning PostgreSQL 11 - Third Edition

Asynchronous access

In the preceding examples, the cursor.execute() method will block the program for the time a query is executing in the database. When the query is long, the program can be blocked for a long time, which sometimes is not a desired behavior. Psycopg 2 provides a way to execute queries asynchronously. Basically, it means that the Python program can do something else while a long query is being executed by the database server.

To use this feature, the database connection should be created as an asynchronous one. This is done by passing the async=1 argument to the connect() function. The process of connection itself is also asynchronous. Now the Python program should be made to wait until the connection is established. This ...