.A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies). The term "database" refers both to the way its users view it, and to the logical and physical materialization of its data, content, in files, computer memory, and computer data storage. This definition is very general, and is independent of the technology used. However, not every collection of data is a database; the term database implies that the data is managed to some level of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn often implies the use of a general-purpose Database management system (DBMS). A general-purpose DBMS is typically a complex software system that meets many usage requirements, and the databases that it maintains are often large and complex. The term database is correctly applied to the data and data structures, and not to the DBMS which is a software system used to manage the data. The structure of a database is generally too complex to be handled without its DBMS, and any attempt to do otherwise is very likely to result in database corruption. DBMSs are packaged as computer software products: well-known and highly utilized products include the Oracle DBMS, Access and SQL Server from Microsoft, DB2 from IBM and the Open source DBMS MySQL. Each such DBMS product currently supports many thousands of databases all over the world. The stored data in a database is not generally portable across different DBMS, but can inter-operate to some degree (while each DBMS type controls a database of its own database type) using standards like SQL and ODBC.
2.Describe file maintenance techniques (adding records, modifying records,deleting records) and validation techniques.
. File maintenance refers to the procedures that keep data current. File maintenance procedures include adding records to correct inaccurate data or to update old data with new data, and deleting records when they no longer are needed,modifying records, serial records often need to be modified because serial publications exhibit changes that affect their bibliographic elements. Correspondingly, record modifications have consistently represented over one-half of the transactions on the CONSER database in recent years. These activities run the gamut from those that significantly increase the scope of a bibliographic record to more minor modifications that are added for specific needs.
. Validation is the process of comparing data with a set of rules or values to find out if the data is correct. Many programs perform a validity check that analyzes data, either as you enter it or after you enter it, to help ensure that it is correct. Types of validity checks include an alphabetic check, a numeric check, a range check, a consistency check, a completeness check, and a check digit.
3. Discuss the terms character, field, record, and file:
.In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language.
.field,is an open-source software project initiated by OpenEnded Group, for the creation of their digital artworks. It is an environment for writing code to rapidly and experimentally assemble and explore algorithmic systems. It is visual, it is hybrid, it is code-based. We think that it has something to offer a diverse range of programmers and artists.
.record,an item or collection of data.
.file,is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished. Computer files can be considered as the modern counterpart of paper documents which traditionally are kept in offices' and libraries' files, and this is the source of the term.
4.Discuss the functions common to most database management systems:data dictionary, file retrieval and maintenance, data security, and backup and recovery.
:.data dictionaryor metadata repository, as defined in the IBM Dictionary of Computing, is a "centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format." The term "may have one of several closely related meanings pertaining to databases and database management systems (DBMS):
.file retrieval and maintenance:
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