Adaptive Server Enterprise
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|Developer(s)||Sybase - A SAP Company|
|Initial release||May 23, 1980|
|Written in||C, C++|
SAP Sybase Adaptive Server Enterprise (ASE) is Sybase Corporation's (Now SAP AG) flagship enterprise-class relational model database server product. ASE is predominantly used on the Unix platform, but is also available for Windows.
Originally for UNIX platforms in 1987, Sybase Corporation's primary relational database management system product was initially marketed under the name Sybase SQL Server. In 1988, SQL Server for OS/2 was co-developed for the PC by Sybase, Microsoft, and Ashton-Tate. Ashton-Tate divested its interest and Microsoft became the lead partner after porting SQL Server to Windows NT.
Microsoft and Sybase sold and supported the product through version 4.21. In 1993, the co-development licensing agreement between Microsoft and Sybase ended and the companies parted ways while continuing to develop their respective versions of the software.
In 1995, Sybase released SQL Server 11.0. Starting with version 11.5 released in 1996, Sybase moved to differentiate its product from Microsoft SQL Server by renaming it to Adaptive Server Enterprise.
Sybase provides native low-level programming interfaces to its database server which uses a protocol called Tabular Data Stream. Prior to version 10, DBLIB (DataBase LIBrary) was used. Version 10 and onwards uses CTLIB (Client LIBrary).
In 1998, ASE 11.9.2 was rolled out with support for row-level locking and distributed joins and improved SMP performance. ASE 12.0 was released in 1999 providing support for Java, high availability and distributed transaction management. In 2001, ASE 12.5 was released providing features such as dynamic memory allocation and support for XML and SSL among others. Support of an EJB container within the database server along with efficient in-memory connections to the database engine, suggests an object oriented access to the relational data.
In September 2005, Sybase released ASE 15. It includes a rewritten query optimizer that is supposed to increase performance over the traditional optimizer, and support for partitioning table rows in a database across individual disk devices to reduce contention and increase the speed at which the data can be accessed, and "virtual columns" which are computed only when required. Other changes that didn't make it to the initial release but are expected soon are support for column-level encryption and the ability to mount a database dump as a "virtual database" to extract only the information required.
Sybase ASE 15.0 also has many new configuration parameters included in its latest release. Many parameters that were static (which required server reboot for the changes to take place) have been made dynamic (changes take effect immediately) ensuring better performance of the adaptive server with comparably less downtime. For example, in the earlier versions of Sybase ASE (prior to 15), the "tape retention in days" parameter was static, causing problems. Now the number of days that the backup is kept on the tape media without overwriting the existing contents in the production environment was made dynamic in the latest release. See the online documentation for more details.
A single stand alone installation of ASE typically comprises one "dataserver" and one corresponding "backup server". In multi server installation many dataservers can share one single backup server though. A dataserver consists of system databases and user's databases. Minimum system databases that are mandatory for normal working of dataserver are 'master', 'tempdb', 'model', 'sybsystemdb' and 'sybsystemprocs'. 'master' database holds critical system related information that includes, logins, passwords, and dataserver configuration parameters. 'tempdb' is used for storage of data that are required for intermediate processing of queries, and temporary data. 'model' is used a template for creating new databases. 'sybsystemprocs' consists of system supplied stored procedures that queries system tables and manipulates data in them.
ASE is a single process multithreaded dataserver application, it means when server is up and running there is one single OS process.
See also 
- SQL Anywhere
- List of relational database management systems
- Comparison of relational database management systems