Returns an integer representing the backend version.
Applications may use this readonly property to determine the version of the database server they are connected to. The number is formed by converting the major, minor, and revision numbers into two-decimal-digit numbers and appending them together. For example, version 7.4.2 will be returned as 70402, and version 8.1 will be returned as 80100 (leading zeros are not shown). Zero value is returned if the connection is failed.
This example checks if server supports tablespaces: