Tabular Data Stream
From Wikipedia, the free encyclopedia
Tabular Data Stream (TDS) is a protocol, or a set of rules describing how to transmit data between two computers.
The TDS protocol was designed and developed by Sybase Inc. for their Sybase SQL Server relational database engine in 1984. The developers at Sybase realized that there was no commonly accepted application-level protocol to transfer data between a database server and its client. To encourage the use of their products, Sybase came up with a solution through the use of a flexible pair of libraries called netlib, and db-lib.
netlib's job is to ferry data between the two computers through the underlying network protocol.
db-lib provides an API to the client program, and communicates with the server via netlib. db-lib sends to the server a structured stream of bytes meant for tables of data, hence a Tabular Data Stream.
In 1990, Sybase entered into a technology sharing agreement with Microsoft which resulted in Microsoft marketing its own SQL Server — Microsoft SQL Server — based on Sybase's code. Microsoft kept the db-lib API and added ODBC. (Microsoft has since added other APIs, too.) At about the same time, Sybase introduced a more powerful "successor" to db-lib, called ct-lib, and called the pair Open Client.
The TDS protocol comes in several varieties, most of which have never been openly documented because they are considered to be proprietary technology. The exception is TDS 5.0, used exclusively by Sybase, for which documentation is available from Sybase.
A free implementation of the TDS protocol has been developed by the FreeTDS team, this software is licensed under the GPL license.
