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HW_1AChapter 11.1 Define the following terms: data, database, DBMS, database system, database catalog,program-data independence, user view, DBA, end user, canned transaction, deductive database system,persistent object, meta-data, and transaction-processing application.● data - Collection of known facts that can be recorded and have an implicit meaning.● database - Collection of data.● DBMS -It is a software that enables users to create and maintain a database. It helps indefining, constructing, manipulating and sharing databases between different users andapplications.● database system - The DBMS software together with the data itself, sometimes the applicationsare also included.● database catalog - Metadata such as definitions of database objects such as base tables, viewsand other functions are stored.● program-data independence - It is a property of DBMS access programs that allows achange in structure of some file independently from access programs by storing thestructure of data files in the DBMS catalog separately from the access programs.● user view - A view may be a subset of the database or it may contain virtual data that is derivedfrom the database files but is not explicitly stored. Each user may see a different view of thedatabase, which describes only the data of interest to that user.● DBA (Database Administrator) - A person who is responsible for maintenance of a databaseenvironment by directing or performing all related activities to keep the data secure.● End user - User who accesses the database for querying, updating and generating reports.End user is the primary reason for the creation of a certain database.● canned transaction - Standard types of queries and updates which are frequently used by Naiveend users to constantly querying and updating databases.● deductive database system - Database systems which provide capabilities for definingdeduction rules for inferencing new information from the stored database facts.● persistent object - Survives the termination of program execution and can later be directlyretrieved by another program.● Meta-data - Data that describes other data.● transaction-processing application - Application which allows several users at the sametime to update the same data in a controlled manner so that the result of the updates iscorrect.1.3 Discuss the main characteristics of the database approach and how it differs from traditionalfile systems.characteristicstraditional file systemsdatabase approachSelf-describing nature of adatabase systemIn the file system approach,each user defines andimplements the needed files fora specific application to run. Filesystem doesn't contain anymetadataA DBMS catalog stores thedescription of a particulardatabase (e.g. data structures,types, and constraints) Thedescription is called meta-datathis allows the DBMS softwareto work with different databaseapplicationData abstractionNo such data model is presentin file systemA data model is a type of dataabstraction that is used to hidestorage details and present theusers with a conceptual view ofthe databaseProgram data independenceThe structures of data files isembedded in the accessprograms, so many change tothe structure of a file mayrequire changing all programsthat access this fileDBMS access programs do notrequire such changes in mostcases. the structure of data filesis stored in the DBMS catalogseparately from the accessprogramsSupport multiple views of thedataIf any changes are made to thestructure of the files it will affectall the programs, so changes tothe structure of a file mayrequire changing of all programsthat access the fileA view may be a subset of thedatabase or it may containvirtual data that is derived fromthe database files but is notexplicitly storedSharing of data and multi usertransaction processingCresting files over a long periodleads to a possibility ofinformation getting duplicated,this redundancy is storing thesame data multiple times leadsto higher costs and wastage ofspace. This may result in datainconsistency in the application,this is because update is done tosome of the files only and not allthe filesAllowing a set of concurrentusers to retrieve from and toupdate the database.concurrency control within theDBMS guarantees that eachtransaction is correctly executedor aborted. Recovery subsystemensures each completedtransaction has its effectpermanently recorded in thedatabase1.6 Discuss the capabilities that should be provided by a DBMS.● Backup and recovery - DBMS's backup and recovery subsystem is responsible for recovery.● Enforce Integrity constraints - DBMS should provide capabilities for defining and enforcingintegrity constraints for the data. Database designers should identify integrity constraints duringthe database design. DBMS should act differently for different types of constraints. Some ofthem can be specified to the DBMS and automatically enforced. Some must be checked byupdate programs. It can also happen that a data item is entered erroneously and still satisfiesintegrity constraints.● Restricting access - DBMS should provide a security and authorization subsystem, which the DBAuses to create accounts and to specify account restrictions. The DBMS should enforce theserestrictions automatically.● Control redundancy [Normalization] - Redundancy in storing the same data multiple times couldlead to several problems. There is a duplication of effort, storage space is wasted and files thatrepresent the same data may become inconsistent. Data normalization in the database approachensures consistency and saves storage space. However, in practice, it is sometimes necessary touse controlled redundancy to improve the performance of queries (denormalization). DBMSshould have the capability to control any redundancy in order to avoid inconsistencies amongthe files.● Persistent storage for program objects - A complex object in C++ or Java can be storedpermanently in an object-oriented DBMS. That object is persistent since it exists after thetermination of program execution and it can be retrieved later by another program.Object-oriented DBMS typically offer data structure compatibility with one or moreobject-oriented programming languages.● Storage structures for efficient query processing - To speed up disk search for the desiredrecords, DBMS often uses indexes. They are based on tree data structures or hash data that aremodified for disk search. To obtain database records

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