Sigma's applications check and maintain data integrity for the Sigma database. This results in the entire file being sent to the client but necessitates many message exchanges across the network. The Database Server executes each SQL statement and passes the results back to the client. ODBC provides a standard SQL interface for sending requests to the server. It allows for the creation of a Transaction Server .
Clients call a remote procedure and pass parameters to it.
This distribution of processing reduces network traffic and improves performance. Site autonomy can also be increased by limiting database modifications to locally executing applications. The RPC mechanism makes it appear the client is directly calling a procedure, located on a remote server, as if it was calling a local procedure. Actually, the client application calls a local stub procedure instead of the actual remote procedure. On the server side, the RPC run-time library API functions accept the request and call the server stub.