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Unformatted text preview: ributes, and so on. Examples of the dynamic
properties include interaction between data items, operations on data items, user
interaction, and so forth.
There is a general consensus that the object-oriented database model is the most
suitable model for multimedia databases. In most cases, multimedia data types are
implemented as classes, having attributes and methods to support each data type.
They may be part of a large class hierarchy or framework. A framework goes
beyond a simple type definition to give more complete support for the data types,
including several methods and additional supporting classes (to import, view, and
export). While type frameworks focus on type-specific support, a database model
for multimedia databases must also have features to express several kinds of
relationships between multimedia data types for composition and presentation.
Hence, a database model for multimedia databases goes much beyond an ordinary
object-oriented database model used for modeling traditional databases.
Support for Multimedia Data Manipulation
A database management system needs to provide support for easy manipulation of
the data stored in a database. Implementing features for manipulation of simple
data types is simple, but it is not a simple task for multimedia data. Multimedia
databases require multimedia data manipulation languages (DMLs) or constructs
with features to support not only simple cut or crop operations on multimedia data,
but also to ensure that these operations adhere to the spatial, temporal, and
synchronization constraints discussed before. For example, to main the temporal
constraints, these operations must provide predictable and worst-case information
about the operation overhead. This lets the system determine if quality of service
(QoS) guarantees can be met when the operation is inserted within the data stream
between the source (database server) and the sink (the viewer).
Another concept related to data manipulation used in multimedia database
management systems is that of derived data. A modified data needs to be stored i...
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- Spring '14