ASA Database Administration Guide
Adaptive Server Anywhere as an Open Server
This chapter describes how Adaptive Server Anywhere fits into the Sybase Open Client/Open Server client/server architecture. This section describes the key concepts of this architecture, and provides the conceptual background for the rest of the chapter.
If you simply wish to use a Sybase application with Adaptive Server Anywhere, you do not need to know any details of Open Client, Open Server, or TDS. However, an understanding of how these pieces fit together may be helpful for configuring your database and setting up applications. This section explains how the pieces fit together, but avoids any discussion of the internal features of the pieces.
Adaptive Server Anywhere and other members of the Adaptive Server family act as Open Servers. This means that you can develop client applications using the Open Client libraries available from Sybase. Open Client includes both the Client Library (CT-Library) and the older DB-Library interfaces.
Open Clients and Open Servers exchange information using an application protocol called the tabular data stream (TDS). All applications built using the Sybase Open Client libraries are also TDS applications because the Open Client libraries handle the TDS interface. However, some applications (such as Sybase jConnect) are TDS applications even though they do not use the Sybase Open Client libraries—they communicate directly using TDS protocol.
While many Open Servers use the Sybase Open Server libraries to handle the interface to TDS, some applications have a direct interface to TDS of their own. Sybase Adaptive Server Enterprise and Adaptive Server Anywhere both have internal TDS interfaces. They appear to client applications as an Open Server, but do not use the Sybase Open Server libraries.
Adaptive Server Anywhere supports two application protocols. Open Client applications and other Sybase applications such as Replication Server and OmniConnect use TDS. ODBC and Embedded SQL applications use a separate application protocol specific to Adaptive Server Anywhere.
Application protocols such as TDS sit on top of lower-level communications protocols that handle network traffic. Adaptive Server Anywhere supports TDS only over the TCP/IP network protocol. In contrast, the Adaptive Server Anywhere-specific application protocol supports several network protocols, as well as a shared memory protocol designed for same-machine communication.
Sybase applications and Adaptive Server Anywhere