Figure 2 illustrates the client/server relational architecture of PSQL. The client talks to the SQL Connection Manager on the server through TCP/IP. This architecture applies to the server engine and to the Workgroup engine (in the case where a client DSN is used to connect from the local Workgroup engine to the remote Workgroup engine).
Figure 3 illustrates the Workgroup relational architecture when a DSN is used to connect from the local Workgroup engine to the remote database, assuming that a remote Workgroup engine is acting as a Gateway to the remote data.