Functional principle

One of the most important features of a Data Stream Management System is the possibility to handle potentially infinite and rapidly changing data streams by offering a flexible processing at the same time, although there are only limited resources like a limited main memory. The following table provides various principles of DSMS and compares them to traditional DBMS.

Database management system (DBMS) Data stream management system (DSMS)
Persistent data (relations) volatile data streams
Random access Sequential access
One-time queries Continuous queries
(theoretically) unlimited secondary storage limited main memory
Only the current state is relevant Consideration of the order of the input
relatively low update rate potentially extremely high update rate
Little or no time requirements Real-time requirements
Assumes exact data Assumes outdated/inaccurate data
Plannable query processing Variable data arrival and data characteristics

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