User Guide

SAP AG November 2002
The database catalog is made up of a number of sections. One section consists of the
information about the installation of the database system and the metadata with the
definitions of users and user groups. This section is not assigned to any user or user group.
For each user or user group, the catalog contains a section in which the metadata of the
objects generated by this user or user group is stored. This includes metadata on Basis
tables, view tables, and so on.
A user can only access the metadata of another user or another user group if authorized to do
so.
Database Instance
The SAP DB database can be installed and run on a computer in one mode (database
instance) or several modes (database instances) (Database Instance Type [Page 132], see
also:
24 ).
SAP DB Versions and Database Instance Types [Page
]
Every database instance consists of threads [Page
15 ]1 , main memory structures (
) and .
caches
[Page 129] volumes [Page 153]
The following volumes are available for each database instance:
• One or more
130
Database
instance
Threads
Caches
Volumes
data volumes [Page
]
• One or more log volumes [Page
144]
Each database instance differentiates between the following areas for the logical storage of
data:
Database catalog [Page
131]
•
Application data [Page
12 ]5
•
Database Instance Type
The SAP DB database system supports different application areas. The SAP DB database
instance [Page 132] has different characteristics depending on the application area. The
following database instance types exist:
SAP DB OLTP [Page
149]
•
• liveCache [Page
14 ]0
• SAP DB Document Server [Page
147]
• SAP DB OLAP [Page
149]
User Manual: SAP DB 132