Definition Data base management system is a system in which “related data”is stored in an “efficient” and “compact” manner. “Efficient”=data which is stored in the DBMS is accessed in very quick time “compact”=means that the data which is stored in DBMS covers very little space in the computer‘s memory “related data“=the data which is stored in the DBMS is about some particular topic.
A DBMS is a set of software programs that controls the organization, storage, management, and retrieval of data in a database.
The DBMS accepts requests for data from an application program and instructs the operating system to transfer the appropriate data.
In large systems, a DBMS allows users and other software to store and retrieve data in a structured way.
Many DBMS packages provide Fourth-generation programming language (4GLs) and other application development features.
Database Servers Database servers are computers that hold the actual databases and run only the DBMS and related software. Database servers are usually multiprocessor computers, with generous memory and RAID disk arrays used for stable storage.
Multimedia Databases Multimedia data typically means digital images audio video animation and graphics The acquisition, generation, storage and processing of multimedia data in computers and transmission over networks have grown tremendously in the recent past.
Multimedia Databases Contents of MMDB Media data - actual data representing images, audio, video that are captured, digitized, processed, compressed and stored. Media format data - Contains information pertaining to the format of the media data after it goes through the acquisition, processing, and encoding phases. E.g. sampling rate, resolution, frame rate, encoding scheme etc.
Multimedia Databases Contents of MMDB 3. Media keyword data (content descriptive data ) Contains keyword descriptions, relating to the generation of the media data. E.g., for a video, includes the date, time, place of recording , person who recorded, scene that is recorded etc.
Multimedia Databases Contents of MMDB Media feature data(content dependent data) - Contains the features derived from the media data. A feature characterizes the media contents. E.g., info about the distribution of colors, the kinds of textures and the different shapes present in an image.
Multimedia Databases Querying parameters 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.
Distributed Databases A distributed database is a collection of multiple, logically interrelated databases of the same system distributed over various sites of a computer network. Sometimes "distributed database system" is used to refer jointly to the distributed database and the distributed DBMS.
Distributed Databases 2 aspects of a distributed database:
Data are not resident at the same site, so that we can distinguish a distributed database from a single, centralized database.
2.Logical correlation :
Data have some properties which tie them together, so that we can distinguish a distributed database from a set of local databases or files which are resident at different sites of a computer network.
All major social and professional networking sites use distributed databases
Each record (document) might have a different
format (number and size of fields)
Don’t store data in tables with uniform sized
fields for each record. Instead, each record is stored as a document that has certain characteristics.
Any number of fields of any length can be
added to a document.
Fields can also contain multiple pieces of data.
Document-oriented database <?xml version="1.0" encoding="ISO-8859-1" ?> <Student> <FirstName>Anna</FirstName> <Address>Denver</Address> <Hobby>singing</Hobby> </Student> A document: FirstName=“Anna“, Address=“Denver“ Hobby="singing" Another document : FirstName=“Anurag", Address=“Thane“ Hobby=“dancing” NickName=“mishra” How will the XML Look like <?xml version="1.0" encoding="ISO-8859-1" ?> <Student> <FirstName>Anurag</FirstName> <Address>Thane</Address> <Hobby>dancing</Hobby> <NickName>mishra</Nickname> </Student> How will the XML Look like