DB2® Server for VM
DB2 Server for VM is a relational database management system. Relational means that the data is organized in table format. Each table has a certain number of columns and rows with data at each intersection. A database management system controls the storing and retrieval of this data.
- Allow multiple users to share data and update data
- Control multiple users from updating at the same time
- Ensure row level security (control who accesses the data)
- Avoid inconsistencies
- Enforce data processing standards
- Access groupings of data with common characteristics
- Preserve data integrity.
DB2 Server for VM is a z/VM® and SAA supported database system. DB2 Server for VM is a separately orderable licensed program. DB2 Server for VM simplifies data handling by offering facilities for querying data, manipulating data, and writing reports. It also contains data recovery and data security measures.
DB2 Server for VM allows you to run applications in either single user mode or multiple user mode. In multiple user mode, one or more users or applications can access the same database. DB2 Server for VM controls the access of data by allowing you to grant privileges to specific users on certain data or to give users access to only part of the information in a table. That is, you can control what rows in a table other users can access. Data access is at the row level.
To prevent two applications from updating the same information at the same time, DB2 Server for VM uses an automatic locking system. There are two types of locks: exclusive locks and share locks. Exclusive locks prevent other applications from reading or modifying data that your application is using. Share locks permit other applications to read data your application is using, but prevent other applications from modifying the data.
DB2 Server for VM preserves data integrity by using logical units of work. A logical unit of work is a sequence of SQL statements that DB2 Server for VM treats as a single unit. Similar to the work units in SFS, either all changes in a logical unit of work complete successfully or none of them complete.
Your applications can use Structured Query Language (SQL) statements to access and manipulate data stored in the DB2 Server for VM database. (INSERT, DELETE, UPDATE)
For more details, see Using DB2 Server for VM.