Adaptive Server Enterprise
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|Developer(s)||Sybase - An SAP Company|
|Initial release||May 23, 1980|
|Written in||C, C++|
SAP Sybase ASE (Adaptive Server Enterprise) which is commonly known as ASE or just Sybase DB, is a relational model database server product for businesses developed by Sybase Corporation which became part of SAP AG. ASE is predominantly used on the Unix platform, but is also available for Microsoft 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 4.2.1.
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. Sybase released SQL Server 10.0, which was part of the System 10 product family, which also included Back-up Server, Open Client/Server APIs, SQL Monitor, SA Companion and OmniSQL Gateway.
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 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 11.5 added Asynchronous prefetch, case expression in sql, the optimizer can use a descending index to avoid the need for a worktable and a sort. The Logical Process Manager was added to allow prioritization by assigning xecution attributes and engine affinity.
In 1998, ASE 11.9.2 was rolled out with support for data pages locking, data rows (row-level locking), distributed joins and improved SMP performance. Indexes could now be created in descending order on a column, readpast concurrency option and repeatable read transaction isolation were added. A lock timeout option and task-to-engine affinity were added, query optimization is now delayed until a cursor is opened and the values of the variables are known.
In 1999, ASE 12.0 was released, providing support for Java, high availability and distributed transaction management. Merge joins were added, previous all joins were nested loop joins. In additional cache partitions were added to improve performance.
In 2001, ASE 12.5 was released, providing features such as dynamic memory allocation, an EJB container, support for XML,SSL and LDAP. Also added was compressed backups, unichar UTF-16 support and multiple logical page sizes 2K, 4K, 8K, or 16K.
In 2005, Sybase released ASE 15.0. It included support for partitioning table rows in a database across individual disk devices, and "virtual columns" which are computed only when required. In ASE 15.0, many parameters that had been static (which required server reboot for the changes to take place) were made dynamic (changes take effect immediately). This improved performance and reduced downtime. For example, one parameter that was made dynamic was the "tape retention in days" (the number of days that the backup is kept on the tape media without overwriting the existing contents in the production environment).
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 per engine.
SAP also has a developer edition that can be used for free to develop against (but not for production use). It only allows 1 engine and 25 connections. There is also an SAP Sybase ASE, express edition available which is limited to 1 server engine, 2 Gb of memory and 5 Gb of disk space per server. This edition is free for production purposes.
- SQL Anywhere
- List of relational database management systems
- Comparison of relational database management systems
- Litchfield, David (2005). The Database Hacker's Handbook: Defending Database Servers. Hungry Minds. p. 196. ISBN 8126506156.
- Gunderloy, Mike; Sneath, Tim (2001). SQL Server's Developer's Guide to OLAP with Analysis Services. SYBEX. p. 26. ISBN 0782153178.
- Harris, Scott; Curtis Preston (2007). Backup & Recovery: Inexpensive Backup Solutions for Open Systems. O'Reilly. p. 562. ISBN 0596102461.