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Glossary

This glossary includes vocabulary for developing common database applications as well as more technical vocabulary that might be used by dedicated database programmers.

BY LETTER: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

ascending sort - any sort which arranges records from lowest value to highest value. Alphabetical and numeric sorts are ascending sorts.

action query - a type of query found in SQL databases which search for a subset of records and then performs an action such as a batch delete or batch update.

AND operator - a type of Boolean operator in which examines two or more conditions and calculates TRUE only if both conditions are also TRUE. For instance a search string of "female" and "age < 21" would return patient records for young women under 21.

autonumber field - a field that is set up so that a number is automatically entered and increases by one for each new record. This can be used to automatically create record numbers, patient or subject numbers, invoice numbers or other similar tracking numbers.

B

backend - Many programs especially online programs need to store and access different types of data in order to function properly. This data is stored in a database, but is called a "backend" because users do not typically see "database" like elements such as a search screen or data entry screen.

batch - a group of records or data, sometimes but not always necessarily related. Databases on mainframe computers perform data operations in batches. "Batch processes" refer to those affecting more than one record at a time.

binary number (base 2) - a number system in which each place is either 1 or 0. This is also called "Base 2" because each place is a power of two (the 2's place, the 4's place, 8's place, and so forth). All computer data is stored as binary data but is converted by the operating system to decimal numbers, text strings, color values, audio frequencies and more depending on the software application.

bit - a unit of data corresponding to a "1" or "0" in a binary number. A boolean field is a size of 1 bit because only one unit of data is stored - a "1" for true or "0" for false. Eight bits together form a byte.

Boolean data type - a field which stores either a TRUE or a FALSE value. Alternate representations of Boolean values include "YES/NO", checked or not checked or (-)1 (True) vs. 0 (False). These are used to

Boolean operator - operations which evaluate multiple boolean variables and determine whether the final product is TRUE or FALSE. Boolean operators include AND, OR and NOT. Boolean operators can also be used to more precisely determine search parameters.

browse mode - a mode in which you can view a list of keywords, categories or records in one page. If you are unfamiliar with the contents of a database, the browse mode can help you understand how the content is organized. Similar terms include sitemap, directory or show all records. This is contrasted with search mode, or using a search form.

byte - a unit of 8 bits. Bytes can be combined to form larger units of memory such as a kilobyte (K) or 1024 bytes.

C

case changing operations - a series of functions which can convert a string of characters to all upper case, all lower case or first word capitalized.

case sensitive - a database or program in which the upper case version of a letter is treated as a distinct item from a lower case version of the letter.

CGI- a program which runs over the Internet via online forms. CGI's can be in any number of languages such as Perl.

character - one letter or number in a string a text. Although letters are usually text, numbers can be either numeric if calculations are required or be a string of characters (e.g. a social security number) if only the digits need to be stored.

client - the application which is used to view the data. Some types of data can be viewed in more than one type of client. For instance, a Web page opened in a browser looks like a typical Web page with formatted text and images, but the same file opened in a text editor will display the HTML code only with no formatting or images.

comma delimited (.csv) file - a basic format for electronic data in which columns separated by a single comma are set up each field and each record is set up one per row with data for each field set in the appropriate column (see example below). This format as well as the tab delimited file are recognized by almost all database applications for import.

Comma Delimited Data Example

Last Name, First Name, Userid, College, Year, G.P.A.
Kirk, James T., jtk000, Communications, Junior, 3.85
McCoy, Leonard, lxm000, Science, Senior, 4.00
Scott, Montgomery, mxs000, Engineering, Senior, 4.00

complex sorts - a sort where records are sorted by one field then each group of records is sorted by another field. For instance, records may be sorted by keyword category, then each category sorted alphabetically by title.

concatenate - to join two text strings together. For instance, a Penn State Access ID (e.g. xyz123) is created by concatenating a person's initials (xyz) with the next available number.

D

data type - the format of the data in a field. Common data types include text, numerical, long integer, Boolean (true/false), date or time.

date (data type) - fields in databases can be set to store dates as special class of data. Specifically, dates are actually assigned specific numbers in a sequence. For instance December 31, 1999 is day number 35063 and January 1, 2000 is day number 35064 in the operating system. This convention allows databases to calculate durations and reccurring events more efficiently.

database - a set of data or information organized into one or more categories. Data can be stored electronically in computer databases, spreadsheets, charting packages or in non-electronic forms such as a phonebook, address book, calendar card catalog or weekly grocery list.

decimal number (base 10) - this term can be used to refer to normal base 10 numbers in contrast with binary or hexadecimal numbers.

default entry (field) - many databases like Filemaker Pro allow you to set up default values for some fields, such as U.S.A. as the default country. This is useful or items where entries in a particular field are set to one value most of the time.

descending sort - any sort which arranges records from highest value to lowest value. Reverse alphabetical and reverse chronological (most recent to least recent) sorts are descending sorts.

dynamic page - A type of Web page in which information from an electronic database is merged or pushed into a template. Dynamic pages are used to show online search results, materials from Web tools such as the ANGEL course management tool or event pages which are constantly updated.

E

existence search - a type of search in which the user knows the criteria but is not sure if the item exists, so the user may need to see a list of available record within a given set of categories. The criteria may not be as specific as for a single item search, but not as general as an exploratory search (browse).

exploratory search - a type of search in which the user may know a vague topic only, but not know what is available in that topic. Users need to examine a variety of data before further narrowing the search. Browsing is often a better strategy for exploratory searches.

export - a process in which electronic data is converted and copied into another file which can then be imported into another database.

F

field - a category in which you can store and sort data for an individual record. An address book database might includes such as family name, personal name, phone number, record number and so forth. In a spreadsheet or tabular list, a column heading typically refers to a data field.

filtering data - another name for the search operation in which a subset of data is selected depending on desired criteria.

Filter mode (Access search) - Access users in a form or data entry screen can search items by clicking a funnel icon and entering search keywords in an appropriate form.

Find mode (Filemaker search) - Filemaker users in a form or data entry screen can search items by entering Find mode and typing search keywords in an appropriate form.

flat file databases - a database in which all data is stored in a list or table in one only file. Modern versions of flat-file databases include EndNote and Excel. Older databases such as dBase III and older versions of Filemaker stored data in flat files. Most recent databases are relational are quasi-relational.

flat directory structure - a directory which contains files only and no sub directories or folders.

form - a name for a screen in which one or more fields are displayed on a computer screen and users are required to enter some kind of input. Examples include search forms and data entry forms.

full-text database - A database which includes text passages. Typical examples of a full text database would be newspaper databases, but could also include a database for searching lesson plans or historical records.

G

geographic information system (GIS) - software which converts numerical geographic, environmental or demographic data into maps.

global constant - In Filemaker, a value which is used in calculations across multiple records. A global constant, like a currency exchange rate, may fluctuate over time and so may need to be updated frequently in a database.

H

hierarchical data - data that is organized into categories and subcategories or a "taxonomy." For instance Penn State employees are listed by campus, then college, then department. Hierarchical data can often be represented as a data tree. See a sample Hierarchical listing below.

Penn State University

University Park

College of Liberal Arts

Department of English

hexadecimal (base 16) number - Base 16 numbers are used some elements of computer programming because they are a multiple of binary numbers, but are for human readers to process and organize. The most commonly seen use of hexadecimal numbers is in the designation of Web page colors.

I

import - a process in which electronic data from a another file or database is copied and included in the database. Some imports also convert data from one file type to the file type of the database.

indexing

inverse subset - the results of a NOT search. These are search results which exclude a certain criteria.

K

key field - a field in a table within a relational database which matches a key field in another related table. They key field is used to tie data from two tables together.

keywords - a term referring to a field which lists the major topics within an associated article or record. Keywords are used to streamline search operations and are also a part of metadata fields for full-text databases.

known-item search - The technical information architecture term for a single item search.

L

lookup field - a field in a relational or quasi-relational database which refers to a field in another table or database in order to generate a drop-down list of possible values.

M

mail merge - an application in which a set of addresses from a data file are merged into a template of a letter or mailing label to create a series of documents based on the template and including the addresses from the data file.

metadata - Literally "about data", this terms refers to searchable index fields used to organize a body of larger documents, objects or content. For instance, in a searchable archive of image files, the "meta data" would refer to searchable fields such as artist name, title, year and so forth; the "content" would be the image file itself. For a news archive, the metadata would be the date, author and topic, and the content would be the actual story itself.
NOTE: Not all databases have a content/metadata architecture.

N

NOT (Boolean Operator) - Used in searches to select data which falls outside a certain criteria. For instance, if you wanted to find a class of resource at Penn State available outside of University Park, you would specify "NOT University Park." This is also called an inverse subset; that is you find University Park resources to exclude them from a report.

(is) null data search - a search which targets fields which contain no data. You can also construct searches which look for fields with any data in them. These are typically used for database maintenance but can also be used to distinguish complete records from incomplete records.

O

OBDC

OR operator - a type of Boolean operator in which examines two or more conditions and calculates TRUE only if either of conditions is TRUE. For instance a Web search string of "Macintosh" and "Mac" would return records referring to both "Mac" and to "Macintosh."

P

partial string search - the same thing as a wildcard search, except that no special wild card character is needed. The search examines all records to see if the search term characters occur anywhere in the field. For instance "Californ" would find records with both "California" and "Californian" in them.

predefined search - buttons, menu selections or links which triggers a search or query based on predetermined search criteria. Daily reports may work for a predefined search based on the current date. Category links in an online database may be a predefined search for that category.

primary sort - in a complex sort, records are first sorted on a primary criteria, then each group is sorted in a secondary or tertiary sort.

Q

query - In SQL, this is a command to search for records in a database defined by criteria specified in a query. When you fill out a search form, you typically trigger a query.

query delete - a query in which records selected by the search criteria are deleted. This may be used for batch deletes of outdated records.

query update - a query in which records selected by the search criteria have a field updated to a designated value. This is used for batch updates in databases or as a way to add information to old records.

query append - In SQL, a way of adding or importing a large set of records to a database records may originate from a delimited file or another database.

R

range - setting a low value and high value in a search. For instance, a search for records of 18-35 year olds would have a range of 18-35.

read only permissions - database permissions settings in which users can search for data, but not edit or delete it.

record - a single data entry with some or all database fields specified. For instance an address book record would refer to one person along with his or her name, phone number, and so forth. In a spreadsheet or tabular list, a row may correspond with a record.

relational databases - a database architecture in which data is accessed via a series of linked tables.

relationship - the type of link specified between tables in a relational database.

report - a report displays records fitting a specific search criteria in a list, usually in some some kind of sort such as numeric, alphabetic or chronological.

S

screen (data entry vs. screen) - what the viewer sees on a computer monitor when interacting with a database. Screens are usually divided into data entry forms, search form and results /reports.

search form - a screen in which a user enters criteria for a search. On the Web, search screens are divided into basic search screens in which only a few criteria can be entered and advanced search screens in which more criteria are available. In Filmmaker and Access, search screens often mirror data entry screens.

search mode - a mode in which a user enters keywords into a search field so that a list of search results can be displayed. This is contrasted with browse mode, of searching through a list of categories.

secondary sort - in a complex sort, records are first sorted on a primary criteria, then each group is sorted in a secondary or tertiary sort.

serial number - A field created in most electronic databases which assigns a sequential record number to each new record as it is created. This is one to ensure that each record has at least one field with a unique value shared by no other record. This can be useful for tracing the history of the entry of a series of duplicate items.

server - a networked computer which stores a single set of data or set of files which can be accessed by more than one computer. Some servers are networked to the Internet and are potentially accessible to the public, while others are networked locally within one office or department.

single item search - a type of search in which the user already knows which item or record he or she needs to see. This is categorized by the user entering very specific criteria with the goal of only a few search results, preferably one. Also referred to as known item searching within information architecture.

sorts - this refers to how records are organized in a table or report. Databases can be sorted on different fields depending on what the user needs to see at the moment. Different types of sorts can include alphabetical, numerical, chronological, geographic or others depending on the data.

SQL ("sequel") language - Structured Query Language. A high-end computer language used to encode large databases. Simple databases such as Filmmaker Pro or Access can be used without knowledge of SQL, but others such as DB2 or Oracle must be programmed in SQL. Most Web databases use a SQL backend because they are generally optimized for processing speed.

string (text) - Any series of characters can be called a text string. The term "string" is usually used to distinguish numbers stored as text (e.g. a social security number) versus a true number needed for calculations.

strip or trim characters - the use of text operations to extract part of a text string, such as the leftmost or rightmost characters in a field.

T

tab delimited text file - a basic format for electronic data in which columns separated by a single tab are set up each field and each record is set up one per row with data for each field set in the appropriate column (see example below). This format as well as the comma delimited file are recognized by almost all database applications for import.

tab order - the tab order determines the sequence of fields a cursor moves to on a screen when the Tab key is pressed. The default order is useful in many situations, but may need to be modified for complex screen.

Tab Delimited Data Example

Sample Student Data
Last Name	First Name	Userid	College	Year	G.P.A.
Kirk	James T	jtk000	Business	Junior	3.85
McCoy	Leonard	lxm000	Science	Senior	4.00
Scott	Montgomery	mxs000	Engineering	Senior	4.00

table (relational database) - the table is where data for a particular portion of a database is stored. It is typically organized into rows (records) and columns (fields). Most complex databases do not let users view tables directly, but instead display data via different screens and reports which pull data from one or more tables.

table view - a view in Filmmaker in Access in which records are displayed in columns and rows similar to a spreadsheet. Table view is one way to examine and sort a group of records efficiently.

taxonomy - the organization of categories and subcategories for a set of data. For instance, biologists organize

text data type - data which is stored as a series of letters. Text can also include strings if numeric codes such as a zip code or social security number.

text operation - a series of operations found in many database applications which let you manipulate text strings. Text operations including concatenation (joining text) and stripping (extracting parts of text)

time data type - a more complex form of the date data type in which the time of day is included. Time fields can show time of day only or both date and time.

time stamp - an operation in which the database program marks the time when a file or database record was changed or midfield. This is useful for tracing the history of when data was changed or modified.

U

update query - In SQL, a type of command which searches for record fitting the specified criteria, then updates a field in that set to a specified value.

V

validation (data entry) - operations programmed into a database application which force users to enter an appropriate value for a particular field. Types of validation can include:

non-empty field - users cannot leave a particular field empty
non-duplicate entry - users cannot insert the same value that exists in another record
range - users can only enter values within a specific range
fixed list - users can only select a value from a drop-down menu
numeric data type - users can only enter a number in a number field
fixed length - users cannot enter values longer than that allocated for a field.

W

wildcard search - a type of search in which certain elements are allowed to be variable. For instance, many databases allow searches to include the asterisk to represent one or more undetermined characters as in Brit* to search for both "Britain" and "British."

write permissions - permissions setting for databases which allows users to edit data. A password may be required for write permissions.

X

X.M.L. (extensible markup language) - A language in which data can be described by custom tags, much like those found in HTML. XML files can be imported into databases or may be viewed online depending on the context. For instance, blogs and newsreaders use the RSS XML standard to display news items.

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Last Update: September 6, 2005