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Unformatted text preview: es The storage hierarchy
typically consists of primary storage (such as random access memories),
secondary storage (such as magnetic disks), and tertiary storage (such as CD
jukeboxes, or magnetic tape libraries). In a hierarchical storage system like this,
performance of data retrieval depends on the efficiency of the migration
mechanisms used to assign the multimedia data items to the optimal level in the
storage hierarchy. The requirement of huge storage capacity is often taken care of,
to a large extent, by using data compression and decompression techniques
(described in Chapter 19).
Hence a multimedia database management system typically requires mechanisms
for handling huge data storage (possibly comprising of multi-level hierarchy),
migrating data automatically from one level to another in the storage hierarchy for
efficient data retrieval, compressing and decompressing data at the time of storage
and retrieval respectively, and transferring and distributing huge volumes of data
across the network.
Support for Multimedia Data Types Multimedia database management systems must provide type support for common
multimedia data types. That is, it is not sufficient for a multimedia database
system to serve only as a repository of multimedia data, but the database system
must also be intelligent enough to understand the data it manages. Hence it must
have the capability to recognize and operate on several standard multimedia data
formats, such as JPEG, GIF, and MPEG. Internally, a multimedia database
management system may support a single (perhaps proprietary) data format for
each data type. For example, all types of multimedia data may be treated internally
as Blobs (binary large objects), as in simple data repositories that do not recognize
or support multimedia data formats. In this case, the multimedia database system
must have conversion routines to convert data from original format to internal
format on import to the database, and from internal format to original format on
export from the database.
Some multimedia data...
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This document was uploaded on 04/07/2014.
- Spring '14