Information Systems Databases Appendix E: Glossary (Intermediate 2) The following are technical terms, which candidates at Intermediate 2 level are expected to be familiar with, and be able to use and interpret correctly in context. Find the correct definition from the definition file. alphanumeric; data usually stored as a text data type consisting of only alphabetic and numeric characters, e.g. EH3 6XX attribute; a property of an entity Boolean; a data type that consists of only two values (usually True/False or Yes/No) complex search; a query which performs a search operation involving multiple search criteria complex sort; a query which performs a sorting operation involving multiple sort criteria data model; a representation of the data to be stored in a database, showing the entities and relationships between them data type; the kind of value that an attribute can have – alphanumeric, Boolean, integer (whole number), link, object, real (real number), text, date, time database; a collection of related data about a set of persons or objects DBMS; Database Management System: software that is used to create, manipulate and present data within a database double precision; type of real data type, which allows for more decimal places. entity; a representation of a set of persons or objects in a data model ER diagram; the way in which the instances of two entities are linked, e.g. oneto one, onetomany, manytomany Field; used to store a single item of data in a database. Corresponds to an attribute in a data model. flat file database; a computerised database in which data is stored within a single table or file foreign key; an attribute that is not a key in its own table, but is a primary key in another table form; used for inputting one set of data to a database instance; an individual occurrence of an entity representing a person or object integer; a data type that represents whole numbers, e.g. 37 key; a field, or set of fields, which can uniquely identify each record of a table in a database layout; the term used for forms and reports link; a data type consisting of a hyperlink to another file, which could be a web page multivalued attribute; an attribute that can have more than one possible value (e.g. a list of names) normalisation; a process used to work out what tables are required and which attributes should be stored in each table in a relational database numeric; a general term for a number data type. Object; a data type that consists of data usually created by another software package, e.g. graphic, sound, video files
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presence check; a type of validation check that indicates whether a value in a field is required or optional. Always applies to key fields. primary key; the key that is chosen to uniquely identify each record of a table in a database primary sort key; in a complex sort, the field which is used first to arrange the records in order query; a means of performing searching, sorting and/or calculations in a DBMS range check; a type of validation check applied to numeric fields to ensure that data entered is within a certain range, e.g. >0 and <=100 real; a data type that represents decimal or fractional numbers, e.g. 3.14. record; stores related fields about a single person or object in a database. relational database; a database in which data is stored within one or more tables that are related checks applied to the values input to ensure they are sensible. relationship; entityrelationship diagram: a graphical representation of a data model report; a means of presenting data extracted from a database for printed output restricted choice check; a type of validation check where the value in a field is selected from a list of values. secondary sort key; in a complex sort, the field which is used to arrange any records which have the same value for the primary sort key single precision; a type of real data type used in some DBMS’s (see double precision) singlevalued attribute; an attribute which can have only one value source document; a paper document used in a manual filling system containing data items required in a computerised database. Examples include order forms, invoices etc table; used to store all records about a person or object in a database. Validation; Check applied to the values input to ensure they are sensible.
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This file contains the terms that are needed for Intermediate 2 Information Systems.