multimedia database a multimedia database mmdb is a collection of related multimedia data the multimedia data include one or more primary media data types such as text images graphic objects including drawings sketches and illustrations animation sequences audio and video a multimedia database management system mmdbms is a framework that manages different types of data potentially represented in a wide diversity of formats on a wide array of media sources it provides support for multimedia data types and facilitate for creation storage access query and control of a multimedia database contents of mmdb a multimedia database mmdb hosts one or more multimedia data types ie text images graphic objects audio video animation sequences these data types are broadly categorized into three classes static media timeindependent image and graphic object dynamic media timedependent audio video and animation dimensional media3d game and computer aided drafting programs comparison of multimedia data types medium elements timedependence text printable characters no graphic vectors regions no image pixels no audio sound volume yes video raster images graphics yes additionally a multimedia database mmdb needs to manage additional information pertaining to the actual multimedia data the information is about the following media data the actual data representing an object media format data information about the format of the media data after it goes through the acquisition processing and encoding phases media keyword data the keyword descriptions usually relating to the generation of the media data media feature data content dependent data such as contain information about the distribution of colours the kinds of textures and the different shapes present in an image the last three types are called metadata as they describe several different aspects of the media data the media keyword data and media feature data are used as indices for searching purpose the media format data is used to present the retrieved information requirements of multimedia databases like the traditional databases multimedia databases should address the following requirements integration data items do not need to be duplicated for different programs invocations data independence separate the database and the management from the application programs concurrency control allows concurrent transactions persistence data objects can be saved and reused by different transactions and program invocations privacy access and authorization control integrity control ensures database consistency between transactions recovery failures of transactions should not affect the persistent data storage query support allows easy querying of multimedia data multimedia databases should have the ability to uniformly query data media data textual data represented in different formats and have the ability to simultaneously query different media sources and conduct classical database operations across them query support they should have the ability to retrieve media objects from a local storage device in a good manner storage support they should have the ability to take the response generated by a query and develop a presentation of that response in terms of audiovisual media and have the ability to deliver this presentation presentation and delivery support issues and challenges multimedia data consists of a variety of media formats or file representations including tiff bmp ppt ivue fpx jpeg mpeg avi mid wav doc gif eps png etc because of restrictions on the conversion from one format to the other the use of the data in a specific format has been limited as well usually the data size of multimedia is large such as video therefore multimedia data often require a large storage multimedia database consume a lot of processing time as well as bandwidth some multimedia data types such as video audio and animation sequences have temporal requirements that have implications on their storage manipulation and presentation but images video and graphics data have special constraints in terms of their content application areas examples of multimedia database application areas digital libraries newsondemand videoondemand music database geographic information systems gis telemedicine databases multimedia oracle multimedia spatial database spatiotemporal database 