SAP Basis

Unit 1: Fundamentals ADM100
Caution: There are a number of different definitions for the term
“central instance”. You should emphasize the definition above, as
it is realized in almost all SAP systems. From the point of view of
downtime security, distributing the essential processes would be
equivalent to increasing the probability of system downtime.
Hint: It is possible to install multiple SAP systems in one database.
However, this is not usually the case. UsethekeywordMCOD
(Multiple Components in One Database) to find more information
about this option.
Figure 1: The Elements of an SAP System
It is certainly possible to install two instances of a system or even of
different systems on one server. When configuring two systems (or their
databases) on one server, you should ensure that the two systems are
clearly differentiated, otherwise a conflict situation will eventually occur
during the use of common resources (such as program libraries), especially
if one system is to be upgraded while the other is to continue to be used
with the same release.
Within a company, no SAP System IDs (SIDs) should be assigned more than
once. You can only perform a meaningful data exchange with two systems
with the same SID only with a great deal of effort (renaming the systems).
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