Glossary

AAT (Art and Architecture Thesaurus)

access points

The entryways into a given body of information. With bibliographic material, an index will provide access points to the information in a book, and a subject heading on a catalog card will provide access points into a collection. One of the benefits of digital information is the broadening of potential access points.

ad hoc queries

"Spur-of-the-moment" questions.

architecture - Doug's diagram.

argument

A part of a command. It defines the data being manipulated or controls program execution.

attribute

A characteristic of an entity or object. A detailed piece of information that describes an entity. Different kinds of attributes include single-valued attributes, multi-valued attributes, and derived attributes.

buffer

A reserved block of primary memory that temporarily stores data read from secondary memory. Used to take advantage of the computer's fast primary memory compared to the slower secondary memory, thereby minimizing the number of input/output (I/O) operations between the primary and secondary memories.

CHIN (Canadian Heritage Information Network)

CIDOC ( International Committee for Documentation of the International Council of Museums)

CIMI (Consortium for the Computer Interchange of Museum Information)

client

Any process that requests specific services from server processes. One part of client server computing.

client/server

A computing model that is based on the distribution of functions among two types of independent processes: clients and servers. Clients make requests and servers respond to client requests. Clients and servers may exist in the same computer or they may exist in different computers that are linked by a network. The key feature is the separation of processing tasks. An assortment of network software is the third component, allowing communication between the client and the server, both of which participate in the actual data processing and sometimes the database itself is spread across more than one machine. One advantage of this kind of distributed computing is that changes can be made to any of the components without necessarily changing the others. This allows for faster development cycles as well as more effective trouble-shooting.

client/server architecture

The client/server infrastructure composed of hardware and software to form a system composed of clients, servers, and middleware.

column

In SQL, a field or attribute. The smallest unit of data in a row.

cross platform

A system that is designed to work across more than one platform.

DBMS (Database Management System)

Software that serves as an intermediary between the user and the database. The DBMS translates user requests into the computer code that is required to fulfill those requests. A DBMS helps the user manage the data stored within the database. A DBMS stores the definitions of data relationships (metadata) in a data dictionary, creates the complex structures required for data storage, transforms entered data to conform to the data structures, creates a security system, creates complex structures that allow multiple-user access to the data, provides backup and recovery, and promotes and enforces integrity rules.

data anomaly

A data abnormality that is usually created when data redundancies exist. If data changes are not make in all the redundant data, different versions of the "same" data may yield different results.

data dictionary

A component that stores metadata. Thus, the data dictionary contains the data definition as well as its characteristics and relationships.

data redundancy

Duplicated data that are stored in more than one location.

database administrator (DBA)

The second highest authority in the DBMS hierarchy. Controls other users' access to the system and modifies options that affect all users.

database object

Table, view, index, synonym, or anthing else created and stored in a database.

default

Any setting that is automatically assumed by the system.

EAD (Encoded Archival Description)

embedded SQL

SQL commands used inside a procedural language program.

entity

A "thing" in a real world with an independent existence. Something about which you want to store data; typically, a person, place, object, concept, or event.

facet

One side of something that has many sides. In the context of faceted subject analysis, a facet is one of many aspects of a subject.

foreign key

Data that logically connects two or more tables. A foreign key in one table matches the primary key of another table.

free text

A body of text which can't be assumed to include any regular structure beyond words separated by delimiters (spaces, punctuation, etc.); uncontrolled. Not the same as full text.

full text

When a database includes "full text" this means that it includes the full body of work rather than a pointer to the work (a bibliographic record for example).

gateway

A type of middleware software that is used to translate client requests into the appropriate protocols needed to access specific services. Such software eliminates the requirement to use the same protocols in both clients and servers. A gateway router strips incoming packets of the protocol of the incoming network and encapsulates them in "envelopes" of the protocol of the outgoing network.

GUI (graphical user interface)

Any interface that is graphics-based, rather than text-based.

HTML (Hypertext Markup Language)

The code that must be applied to data to produce desired displays of pages on the world wide web. HTML is a subset of SGML.

hypertext

Hypertext links make it possible to connect or link a passage in a document to another document on the same web site or a document on web site on a machine residing on the opposite side of the world. One click on the link takes the user automatically to the document to which the object that has been clicked on is linked.

index

Data structure used to locate a row in a table without having to read the entire table.

information system

A system that provides for data collection, storage, and retrieval; facilitates the transformation of data into information and the management of both data and information. An information system conprises hardware, software (DBMS and applications), the database(s), people, and procedures.

interface

A connection between two systems or devices.

join

A query that combines columns and data from two or more tables, or two or more columns and data from the same table.

key

Columns in an index that identify a row.

LC (Library of Congress)

LCSH (Library of Congress Subject Headings)

MARC (Machine Readable Cataloging)

metadata

Data about data; that is, data concerning data characteristics and relationships. Our data dictionary is an example of metadata.

middleware

The computer software that allows clients and servers to communicate within the client/server architecture. Also known as the communications layer, composed of an Applications Programming Interface (API), a database translator, and a network translator. Middleware insulates client processes from the network protocols and and the details of the server process protocols.

nesting

Placing a statement within another statement.

network

An interconnected or interrrelated chain, group, or system. Computers that are linked together constitute a network. There are Wide Area Networks (WANs) and Local Area Networks (LANs). The Internet is often referred to as a network of networks, its power derived from its decentralization.

node

A node on a network is formed usually by the presence of a router and user access equipment. Often several leased lines are joined together at a network node. If a network topology is visualized as a road map, the leased lines are the roads and the nodes are the towns into which many roads travel.

OCLC

ontology

A theory concerning the kinds of entitites and specifically the kinds of abstract entities that are to be admitted to a language system.

open architecture

An architecture according to which third-party developers can legally develop products and for which public domain specifications exist.

open platform

The term as used by the Electronic Frontier Foundation (EFF) refers to a system of beliefs that include political goals such as; diversity of information sources, universal service, free speech and common carriage, privacy, and development of public interest applications and services. As we use the term, it refers more to products that based on standards other than platform and consequently are theoretically independent of platform.

operating system

A collection of programs that control and organize the resources of a computer system. These resources consist of hardware components such as computers and printers as well as software programs which instruct the computer to perform specific tasks. UNIX, DOS and Apple's System 7 are examples of different operating systems.

operator

Symbol (+,-,*,/,=, etc.) representing an operation to be performed.

Oracle

Refers both to the company, Oracle Corporation and their product, Oracle Server. They describe the product as a state-of-the-art information management environment. It is a respository for very large amounts of data, and gives users rapid access to that data. The Oracle Server provides for the sharing of data between applications; the information is stored in one place and used by many systems. The Oracle Server runs on dozens of different computers.

outer query

The main query within which nested queries reside.

platform

If one dictionary definition of platform is a plan of action or statement of policy, and another is the grounds for or basis of something; in the context of computerization a platform is the system that you work with. It is not the machine per se, as many companies built computers that are on the PC platform, for instance, and it is not the operating system only (Mac is a platform, System 7 is an operating system; PC is a platform, DOS and Windows are operating systems).

postcoordination

Combining two or more descriptors at the time of retrieval, usually using Boolean operators "and", "or", "not" (Victorian and houses), in order to formulate a query.

precision

precoordination

Combining two or more descriptors at the time of indexing (Victorian houses), in order to formulate a subject statement or object description. Library of Congress Subject Headings are an example of precoordination.

predicate

Part of a search condition that sets the criteria for the search.

primary key

Column or columns that uniquely define each row in a table.

protocol

A protocol is a definition of how computers will act when talking to each other. It is to networking what a programming language is to programming. Standard protocols allow computers from different manufacturers to communicate; the computers can use completely different software, providing that the programs running on both ends agree on what the data means.

query

A database search; a request for information.

query language

A nonprocedural language that lets the user specify what is to be done without specifying how it is to be done. An example of a query language is SQL.

RLIN (Research Libraries Information Network)

recall

relational algebra

A set of mathematical principles that form the basis for the manipulation of relational table contents; comprises eight main functions: SELECT, PROJECT, JOIN, INTERSECT, UNION, DIFFERENCE, PRODUCT, and DIVIDE.

relational database

A data structure that stores information about entities, the attributes of those entities, and the relationships among those entities. Perceived by the user to be a collection of tables.

relevance

The basis for effective communication of knowledge. Relevance is the factor that governs the effectiveness of each communication process. Since the purpose of information retrieval is communication, relevance is also the key ingredient in effective retrieval. A retrieval transaction is considered successful when the retrieved documents are relevant to the patron who requested them. Hence relevance may be thought of as the criterion of retrieval success. Unfortunately, relevance is an abstract notion and an illusive property. As yet, it cannot be precisely defined nor accurately measured. (Kwasnik, Oh : 1995)

result table

Set of rows retrieved by a database search.

row

A set of related columns.

SAA (Society of American Archivists)

SGML (Standard Generalized Markup Language)

SGML is an international standard for electronic document exchange. HTML is a form of SGML.

SQL (Structured Query Language)

A specific set of commands for retrieving data from relational databases. Currently the most popular of query languages, SQL comes in a variety of formats, but the core statements are the same. While developers may add "extensions", the basic commands are consistent, a fact which theoretically enables SQL to function across different machines and different programs.

server

A server is normally thought of as a powerful computer that can answer queries from clients. The client-server function is usually some variation of a database function. That is to say the client asks the server to send information to the client. The client software, usually residing on the machine of each end user, is tailored to work directly with the server software.

subquery

A query that resides within another query

System catalog

A DBMS table that contains data about the database, rather than user data.

TCP/IP (Transport Control Protocol/Internet Protocol)

A suite of networking protocols that lets disparate types of computers communicate. TCP/IP is the standard protocol upon which the Internet is based.

table

Set of columns and rows containing stored information. The basic unit of a database.

thesaurus

transfer protocol

UNIX

A multi-user, multi-tasking operating system originally developed at AT&T Bell Laboratories. UNIX was used to develop a lot of powerful networks that are the basis of the Internet and while other operating systems are the product of a single company, UNIX was developed as a collaborative effort, making UNIX very powerful as well as flexible. It also has resulted in there being several different versions of UNIX.

URL (Uniform Resource Locator)

An addressing scheme used to link resources by way of the WWW. A Web client lets you move directly to any supported Internet resource when you enter a URL address. Example: http://www. mysticseaport.org

view

A temporary (or "virtual") table made up of data from one or more base tables.

Web browser

A Web Browser is client/server software used to query world wide web sites. Mosaic was the first popular browser. Other examples of web browsers are Netscape and Internet Explorer.

Web document

WWW (World Wide Web)

The World Wide Web is software that enables digital data that has been "marked up" with HTML to be put into hypertext databases where data in one database can be linked to data in another so that by clicking on the marked text the user is automatically and transparently logged into the new web server where the linked data is found. In 1994 -1995 the World Wide Web became the driving force behind Internet growth.

Z39.50

Z39.50 is a protocol designed to retrieve information -- both bibliographic and abstract data. When vendors follow a given set of rules their systems can be accessed by other vendors who follow the same rules. Z39.50 is maintained by the Library of Congress, and was created with substantial input from vendors, utilities, information providers and universities. While many of the initial applications of Z39.50 were for use with bibliographic data (online public access library catalogs, for example), the protocol is actually quite general, and search attribute sets can be defined which allow the protocol to work with most other types of data. The Z39.50 protocol allows the researcher to search different types of databases using the same command and display mechanism.

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last updated on 01/22/99