Tabular Data Stream

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Tabular Data Stream (TDS) is an application layer protocol, used to transfer data between a database server and a client. It was initially designed and developed by Sybase Inc. for their Sybase SQL Server relational database engine in 1984, and later by Microsoft in Microsoft SQL Server.

Background[edit]

During the early development of Sybase SQL Server, the developers at Sybase perceived the lack of a commonly accepted application-level protocol to transfer data between a database server and its client. In order to encourage the use of its products, Sybase promoted the use of a flexible pair of libraries, called netlib and db-lib, to implement standard SQL. A further library was included in order to implement "Bulk Copy" called blk. While 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. blk provides, like db-lib, an API to the client programs and communicates with the server via netlib.

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 additional APIs.) At about the same time, Sybase introduced a more powerful successor to db-lib, called ct-lib, and called the pair Open Client. db-lib, though officially deprecated, remains in widespread[quantify] use.

The TDS protocol comes in several varieties, most of which had not been openly documented because they were regarded[by whom?] as proprietary technology. The exception was TDS 5.0, used exclusively by Sybase, for which documentation is available from Sybase.[1] This situation changed when Microsoft published the TDS specification in 2008,[2] as part of the Open Specification Promise.

The FreeTDS team has developed a free native-library implementation of the TDS protocol,[3] licensed under the LGPL license. WireShark has a protocol decoder for TDS.[4]

Oracle Corporation provides Oracle Net - software analagous to TDS.[5]

References[edit]

  1. ^ "TDS 5.0 Functional Specification, Version 3.8" (PDF). Retrieved 2009-07-08. 
  2. ^ "[MS-TDS]: Tabular Data Stream Protocol". Retrieved 2014-04-29. 
  3. ^ Chip Andrews; David Litchfield; Bill Grindlay (2003). SQL server security. McGraw-Hill Professional. p. 260. ISBN 0-07-222515-7. 
  4. ^ protocol/tds, Wireshark.org wiki
  5. ^ "SQL Server Integration Services with Oracle Database 10g". SQL Server Technical Article. Microsoft. May 2008. p. 2. Retrieved 2017-07-20. Oracle Net is analogous to the SQL Server Tabular Data Stream (TDS) transport facility. 

External links[edit]