Data Warehouse Glossary

This glossary contains definitions for terms related to data warehousing at the University of Oregon. Words in italics are in the glossary.

Admin Layer - The part of a Data Model which is supplied by the Data Warehouse Group.

Aggregate Functions - See Group Functions.

Attribute - Also called a field in database parlance, an attribute is a defined item of data that an object can store. Last Name in the Person object is an example of an attribute.

Bi/Query The standard software used with the University of Oregon Data Warehouse. Bi/Query shows the user a graphical representation of the objects in the database, called a data model, and their relationships, and lets the user perform queries based on the model.

Column - A column is a listing of data for a single attribute that has been retrieved from the Data Warehouse by a query. If several attributes are selected for a query, each attribute will have one column in the query results.

Combining Qualifications - When there is more than one qualification in a query, Combining is the act of grouping these connected qualifications so that the desired results are obtained.

Combining Results - Query results may be gathered and then combined to create a single set of results which contains data from more than one query. This is called combining results.

Connection - A connection is an established link between the computer of someone using the Data Warehouse and the Warehouse itself. This link is established by Bi/Query using SQL*Net.

Connective - When a query has more than one qualification, the connectives, AND and OR, are used to determine the relationship between the qualifications. A qualification of A AND B means that only records that meet both qualification A and qualification B will be selected. A OR B means that all records which meet either qualification A or qualification B will be selected. See Combining Qualifications.

Count - An aggregate function which returns the number of rows of a query or some part of a query. Count can be used to return a single count of the rows a query selects, or the rows for each group in a query, such as the number of degrees each student has. See Group Functions.

Cross Tab - Short for cross tabulation, a cross tab is a kind of report. Different attribute labels and their values go down and across the edges of the report. The contents of the report are the counts of records with given values for those attributes. A cross tab report may be created in Bi/Query, or in some other program, such as Excel, using exported data.

Data Dictionary - A dictionary-style listing of the attributes available in the Data Warehouse, grouped by object.

Data Model - A Bi/Query specification of data stored in the Data Warehouse. The data model is supplied by the Data Warehousing Group. Is consists of several screens, each containing icons representing warehouse objects, and lines representing the connections between them. As the warehouse data model changes, it is updated on user's machines by downloading.

Data Values - Lists of legitimate values for a given attribute. For example, the data values for Ethnic Code would be all of the valid ethnic codes that we have specified in Banner.

Distinct - A group function which specifies that only one row will be returned for each unique value. For example, a select distinct on last name would return only one value for "Smith", even if there were 5 different Smiths in the warehouse.

Downloading a Model - The process of getting an updated version of the data model onto a user's computer. The downloading process happens automatically where the Data Warehouse is run.

Driving Object (Table) - In a joined query, the driving object is the object which would return the fewest rows if queried separately. See Choosing Driving Object (Table) in the Hints document.

Field - An alternative term for attribute.

GQL - Graphical Query Language, the old software that gave users access to databases. It has been replaced with Bi/Query

Group Functions - Functions which group rows together in a query to obtain data about the entire group instead of individual rows. Counting and summing are examples of group functions.

Join - A type of query which retrieves data from more than one object at a time. A join allows the user to select attributes from multiple objects, then returns the data as if were all stored together in one object.

Object - Also called a table in database parlance, an object is a single logical grouping of attributes. For example, in the Data Warehouse, the Person object contains attributes such as Last Name and Age. Each object is represented in Bi/Query as a single icon.

Prompt - A user defined question asked when a query is run, whose result is used in the query. For example, a query could be set up to prompt the user for a student ID, then look up data for that student.

Qualification - A condition put on a query so that only certain rows are returned. For example, a query can be qualified to only return students who are Oregon residents.

Query - A single request to the Data Warehouse for information. A query is created in Bi/Query by selecting attributes from one or more objects, and possibly specifying qualifications or group functions to determine the data that is returned. It is then run to retrieve actual data.

Query Results - The actual data that has been retrieved as the result of running a query. A number of things can be done with query results in Bi/Query, such as combining, exporting and reporting.

Record - An alternative name for row.

Report Specification - All of the information needed to take query results and lay them out in a report. This includes page format, subtotals, headings, page numbers, etc. A report specification can be stored for later use, and can also be used with different query results.

Row - A set of values, one for each of the attributes in an object. For example, in the Person object, one person's data, such as name, address, age, etc., would constitute a single row.

Select - To choose the attributes that will be returned as the result of a query.

Sorting - Ordering query results so that a certain attribute is in ascending or descending order. For example, a query on the Person object might be sorted by alphabetic Last Name. Multiple levels of sorting are possible, so that, for example, all of the "Smiths" would be sorted then by First Name.

SQL*Net -The software that Bi/Query uses to connect to the actual Data Warehouse database.

Sub-Query - A special kind of qualification. Instead of using a value as the qualifier, a query is used.

Sum - A group function which adds the values for a group. The attribute involved must be a number. For example, the sum function could be used to return the total number of credit hours students are taking.