Database Information Systems Flashcards
Attribute
the defined property of an entity.
Centralised database
has all its data residing in one place
data dictionary
a list of field names containing information about how the data in each field is to be constructed
data integrity
the accuracy and reliability of data
data matching
used to cross-link data- data is brought together from different sources and compared
data quality
identifies how reliable and effective the data is in a database, involves the accuracy of the data
data redundancy
where the same data is stored in two or more records or files, this is undesirable duplication of data. Redundant data takes up valuable space.
data validation
the process of checking the validity of data at the data entry stage
database
A database is a collection of related data, stored in such a way that meaningful information can be extracted. Files, records, fields and characters are the elements that make up the structure of data in a database.
database administrator
the person who is responsible for the construction of a database and the supervision of operations connected with that database.
distributed database
a database that consists of two or more files located at different sites on a computer network.
entity
the specific thing about which data is collected and stored , separate tables in the schema indicate the entities
file
a collection of related records: a record is a collection of related fields, a field is a subdivision of a record and a character is the smallest unit of data entered into a field
flat-file database
a database system that operates on a single table of data
foreign key
an attribute, which is the primary key of another table
hyperlink
a piece of text or graphic that contains an embedded link to another piece of text, an image or another web page
hypermedia
the storage of information using a set of documents that may contain text, number, images , audio and video
hypertext
a system where documents can be cross-linked in such a way that you can navigate from one document to the next by clicking on hyperlinks, which are electronic connections
metadata
information about data that provides a common ground for people working on a project at the same time
online analytical processing ( OLAP)
a software tool that provides analysis of data stored in a database and is used in data mining
online transaction processing( OLTP)
This refers to a class of systems that facilitates and manage transaction -oriented applications, typically for data entry and retrieval transaction processing.
primary key
a field that stores data that uniquely identifies the record
query by example ( QBE)
a visual method of query where the search criteria is entered into an empty record and the records meeting this criterion will be displayed
query language
a non-procedural language, designed to allow the database user to ask questions of the database
relational database
This works with multiple tables that are linked by key fields
relationship
the way in which entities are related to one another- the key field is used to link entities
schema
an organised plan of an entire database, showing where the data is found and the logical relationships
