Used to set the version of protocol for communication with PostgreSQL server.
property ProtocolVersion: TProtocolVersion default DefValProtocol;
Set ProtocolVersion to pv20 to work with PostgreSQL server version 7.3 or older that don't support protocol version 3.0. Set ProtocolVersion to pv30 to enforce the protocol version 3.0. Set ProtocolVersion to pvAuto to automatically select between protocol versions depending on the specific query. The default value is pvAuto.