Glossary

add-in

A custom extension, written in any language that supports the Component Object Model (COM), usually Microsoft® Visual Basic®, that interacts with the OLAP Manager and provides specific functionality. Add-ins are registered with the OLAP Add-In Manager. They are called by the OLAP Add-In Manager in response to user actions in the user interface.

ADO MD

See Microsoft ActiveX Data Objects (Multidimensional).

aggregate function

In general, a function such as Sum, Count, Min, or Avg that calculates a summary value from one or more sets of input values. In multidimensional expressions (MDX), a function that returns a calculated summary value based on the context of a query and one or two sets of input values.

aggregation

A table or structure containing precalculated data for a cube. Aggregations support rapid and efficient querying of a multidimensional database. See also precalculate.

aggregation prefix

A string that is combined with a system-defined ID to create a unique name for a partition's aggregation table. A default string is generated based on the name of the partition and the name of its parent cube, but a user-defined string of up to 21 characters can be specified to replace the automatically-generated string.

All level

The optional highest level of a dimension, named "(All)" by default. The All level contains a single member that is the summary of all members of the immediately subordinate level.

ancestor

A member in a superior level in a dimension hierarchy that is related through lineage to the current member within the dimension hierarchy. For example, in a Time dimension containing the levels Quarter, Month, Day, Qtr1 is an ancestor of January 1st. See also child, descendant, parent, sibling.

authentication

The operation by which a system verifies a user's logon information.

authorization

The operation that verifies the permissions and access rights granted to a user.

axis

A set of tuples. Each tuple is a vector of members. A set of axes define the coordinates of a multidimensional dataset. For more information about axes, see the OLE DB for OLAP section in the OLE DB documentation.

See also tuple, slice.

calculated member

A member of a dimension whose value is calculated at run time using an expression. Calculated member values may be derived from other members' values. A calculated member is any member that is not an input member. For example, a calculated member Profit can be determined by subtracting the value of the member Costs from the value of the member Sales. See also Calculated Member Builder, input member.

Calculated Member Builder

A dialog box in the OLAP Manager used to create calculated members. You can pick parent members and members from a list. In addition, you can construct calculated value expressions using the cube data and analytical functions provided. See also calculated member.

cell

In a relational database, the addressable attribute of a row and column. In a cube, the set of properties, including a value, specified by the intersection when one member is selected from each dimension. See also coordinate.

child

A member in the next lower level in a hierarchy that is directly related the current member. For example, in a Time dimension containing the levels Quarter, Month, and Day, January is a child of Qtr1. See also ancestor, descendant, parent, sibling.

client application

An application that retrieves data from an OLAP server and performs local analysis and presentation of data from relational or multidimensional databases. Client applications connect to the OLAP server through the PivotTable Service component. See also PivotTable Service.

column

In a relational database, a location in a row in which a particular type of data is stored. Individual columns are characterized by their maximum length and the type of data that can be placed in them. The intersection of a column and row define a cell. A column is equivalent to a field.

commit

To save a change to a database, cube, or dimension.

An SQL COMMIT statement guarantees that all or none of the transaction’s modifications are made a permanent part of the database. A COMMIT statement also frees resources, such as locks, used by the transaction. See also rollback.

coordinate

An element (member or tuple) of an axis. The intersection of a set of coordinates determines a cell. See also cell.

cube

A subset of data, usually constructed from a data warehouse, organized and summarized into a multidimensional structure defined by a set of dimensions and measures. A cube’s data is stored in one or more partitions.

Cube editor

A tool in the OLAP Manager that you can use to create new cubes or edit existing ones. For information on working with the Cube editor, see “Building a Cube with the Cube Editor.”

cube file

See local cube.

data definition language (DDL)

The statements used by an application to define the structure (rather than the contents) of a database, cube, or table.

data explosion

The exponential growth in size of a multidimensional structure such as a cube due to the storage of precalculated data.

data mart

A subset of the contents of a data warehouse, stored within its own database. Data marts usually contain data focused at the department level or on a specific business area. See also data warehouse.

data scrubbing

The process of making data consistent either manually, or automatically using programs. For example, a database with inconsistent data might contain customer addresses that have the State column set to "WA" for one customer, but "Washington" for another. Data scrubbing is performed prior to or during the transfer of data to a data warehouse. See also data transformation.

data source

In general use, the source of data for an object such as a cube or dimension. Also, the specification of the information necessary to access source data. Sometimes refers to a DataSource object. See also data source name.

data source name (DSN)

The name assigned to an ODBC data source. Applications can use DSNs to request a connection to a system ODBC data source, which specifies the computer name and (optionally) database that the DSN maps to. A DSN can also refer to an OLE DB connection.

data transformation

A set of operations applied to source data before it can be stored in the destination using Microsoft SQL Server™ Data Transformation Services (DTS). For example, DTS allows calculating new values from one or more source columns, or breaking a single column into multiple values to be stored in separate destination columns. Data transformation is applied during the process of moving data into a data warehouse.

data warehouse

A relational and OLAP database specifically structured for query and analysis. A data warehouse typically contains data representing the business history of an organization.

dataset

In general, a collection of related information made up of separate elements that can be treated as a unit. In OLE DB for OLAP, the set of multidimensional data that is the result of executing an MDX statement. For more information about datasets, see the OLE DB documentation.

DDL

See data definition language.

Decision Support Objects (DSO)

The OLAP Services server object model. DSO is used to create applications that define and manage cubes and other objects. DSO can also be used to extend the functionality of the OLAP Manager or to automate the ongoing maintenance of your system.

denormalize

To introduce redundancy into a table in order to incorporate data from a related table. The related table can then be eliminated. Denormalization can improve efficiency and performance by reducing complexity in a data warehouse schema. See also star schema.

density

The relative percentage of a multidimensional structure's cells that contain data. OLAP Services stores only cells that contain data. A dense cube requires more storage than a sparse cube of identical structure design. See also data explosion, sparsity.

descendant

A member in a dimension hierarchy that is related to a member of a higher level within the same dimension. For example, in a Time dimension containing the levels Year, Quarter, Month, and Day, January is a descendant of 1997. See also ancestor, child, parent, sibling.

dimension

A structural attribute of a cube that is an organized hierarchy of categories that describe data in the fact table. These categories (levels) typically describe a similar set of members upon which the user wants to base an analysis. For example, a geography dimension might include levels for Country, Region, State or Province, and City. See also level, measure.

Dimension editor

A tool in the OLAP Manager that you can use to create, examine, and edit a dimension and its levels. It offers two views: Schema, which you can use to examine and edit the dimension table structure, and Browse, which you can use to check dimension data.

dimension hierarchy

One of the hierarchies of a dimension. See also hierarchy.

dimension table

A table in a data warehouse whose entries describe data in a fact table. Dimension tables present business entities. A database object stored in a data warehouse containing information used to reference the data stored in the fact table.

drill down/drill up

A technique for navigating through levels of data ranging from the most summarized (up) to the most detailed (down). For example, to view the details of sales data by year, a user can drill down to display sales data by quarter, and further to display data by month.

DSO

See Decision Support Objects.

fact

A row in a fact table in a data warehouse. A fact contains one or more numeric values that measure a data event such as a sales transaction.

fact table

A central table in a data warehouse that contains numerical measures and keys relating facts to dimension tables. Fact tables contain data that describes a specific event within a business, such as a bank transaction or product sale. See also star schema, snowflake schema.

field

See column.

filter

A set of criteria applied to records to show a subset of the records. An SQL WHERE clause expression that specifies a subset of records.

granularity

The degree of specificity of information contained in a data element. A fact table that has fine granularity contains many discrete facts such as individual sales transactions. A table that has coarse granularity stores facts that are summaries of individual elements, such as sales totals per day.

hierarchy

An arrangement of members of a dimension into levels based on parent-child relationships, such as Year, Quarter, Month, Day or Country, Region, State or Province, City. Members in a hierarchy are arranged from more general to more specific.

HOLAP (hybrid OLAP)

A storage mode that uses a combination of multidimensional data structures and relational database tables to store multidimensional data. OLAP Services stores aggregations for a HOLAP partition in a multidimensional structure and facts in a relational database. See also MOLAP, ROLAP.

hybrid OLAP

See HOLAP.

incremental update

The set of operations that adds new members to an existing cube or dimension, or that adds new data to a partition. One of three processing options for a cube or partition. One of two processing options for a dimension. See also process, refresh data.

index

In a relational database, an object that provides fast access to data in the rows of a table, based on key values. Indexes provide quick access to data and can enforce uniqueness on the rows in a table.

input member

A member whose value is loaded directly from the data warehouse instead of being calculated from other data. See also calculated member.

input set

The set of data provided to an MDX value expression upon which the expression operates. For more information about set value expressions, see the OLE DB documentation.

join

An association between a column in one table or query and a column of the same data type in another table or query. A join describes how data between tables or columns is related. A join is the result of executing an SQL JOIN statement.

key column

A column whose contents uniquely identify every row in a table.

level

An element of a dimension hierarchy. Levels describe the dimension order from the highest (most summarized) level to the lowest (most detailed) level of data. For example, possible levels for a Geography dimension are: Country, Region, State or Province, City. See also dimension, hierarchy.

level hierarchy

See dimension hierarchy. See also hierarchy.

library

In OLAP Services, a folder that contains shared objects such as shared dimensions that can be used by multiple objects within a database.

local cube

A cube created and stored with the extension .cub on a local computer using PivotTable® Service. See also PivotTable Service.

MDX

See multidimensional expressions.

measure

A quantitative, numerical column in a fact table. Measures typically represent the values that are analyzed. See also dimension.

member

An item in a dimension representing one or more occurrences of data. A member can be either unique or nonunique. For example, 1997 and 1998 represent unique members in the year level of a time dimension, whereas January represents nonunique members in the month level because there can be more than one January in the time dimension if it contains data for more than one year.

MemberKeyColumn

The property that specifies the identifiers for dimension members. The MemberKeyColumn can specify a column in a table or an expression that, when evaluated, results in a set of member identifiers. For example, a MonthNumber column in a time dimension table would contain numbers in the range 1 to 12, corresponding to the months of the year. See also MemberNameColumn, member variable.

MemberNameColumn

The property that associates names with identifiers for dimension members specified by the MemberKeyColumn property. For example, a MonthName column in a time dimension table would contain the names Jan, Feb, Mar, and so forth, to correspond to the numbers 1 to 12 in the MonthNumber column in the same table. These names are returned to the client when queries are evaluated and can be used to make the presented data more readable. See also MemberKeyColumn, member variable.

member property

Information about the members of a dimension level in addition to that contained in the dimension. For example, the color of a product or the telephone number of a sales representative. For more information about member properties, see the OLE DB documentation.

member variable

The value used internally by OLAP Services to identify a dimension member. MemberKeyColumn specifies the member variables for a dimension. For example, a number in the range 1 to 12 could be the member variable that corresponds to a month of the year. See also MemberKeyColumn, MemberNameColumn.

merge

The operation that combines two partitions into a single partition.

metadata

Information about the properties of data, such as the type of data in a column (numeric, text, and so on) or the length of a column. Information about the structure of data. Information that specifies the design of objects such as cubes or dimensions.

Microsoft ActiveX Data Objects (Multidimensional) (ADO MD)

A high-level, language-independent set of object-based data access interfaces optimized for multidimensional data applications. Visual Basic and other automation languages use ADO MD as the data access interface to multidimensional data storage. ADO MD is a part of ADO 2.0 and later.

Microsoft Management Console (MMC)

Microsoft Management Console (MMC) is an extensible, common console framework for management applications. OLAP Services uses MMC to host its user interface, the OLAP Manager.

MMC

See Microsoft Management Console.

MOLAP (multidimensional OLAP)

A storage mode that uses a proprietary multidimensional structure to store a partition's facts and aggregations. A partition's data is completely contained within the multidimensional structure. See also HOLAP, ROLAP.

multidimensional expressions (MDX)

A syntax used for querying multidimensional data. For more information about MDX, see the OLE DB documentation.

multidimensional OLAP

See MOLAP.

multidimensional structure

A database paradigm that treats data not as relational tables and columns, but as information cubes that contain dimension and summary data in cells, each addressed by a set of coordinates that specify a position in the structure's dimensions. For example, the cell at coordinates {SALES, 1997, WASHINGTON, SOFTWARE} would contain the summary of sales of software in Washington in 1997. See also cube.

ODBC

See Open Database Connectivity.

OLAP

See online analytical processing.

OLAP client

See client application.

OLAP Manager

A Microsoft Management Console (MMC) snap-in that provides a user interface for managing the OLAP server and for designing and creating multidimensional databases, cubes, and dimensions. See also Microsoft Management Console, snap-in.

OLAP server

The server component of OLAP Services that is specifically designed to create and maintain multidimensional data structures and provide multidimensional data in response to client queries. See also PivotTable Service.

OLE DB

A set of interfaces that expose data from a variety of sources using the Component Object Model (COM). OLE DB interfaces provide applications with uniform access to data stored in diverse information sources. These interfaces support the amount of DBMS functionality appropriate to the data source, enabling it to share its data.

OLE DB 2.0 and later includes OLE DB for OLAP, which supports multidimensional data access and querying. For more information about OLE DB, see the OLE DB documentation. See also OLE DB for OLAP.

OLE DB for OLAP

A section of OLE DB 2.0 and later that addresses multidimensional structures and OLAP. See also OLE DB.

OLTP

See online transaction processing.

online analytical processing (OLAP)

A technology that uses multidimensional structures to provide rapid access to data for analysis. The source data for OLAP is commonly stored in data warehouses in a relational database. See also HOLAP, MOLAP, ROLAP.

online transaction processing (OLTP)

A database management system representing the state of a particular business function at a specific point in time. An OLTP database is typically characterized by having large number of concurrent users actively adding and modifying data.

Open Database Connectivity (ODBC)

A database-material application programming interface (API) aligned with the American National Standards Institute (ANSI) and International Standards Organization (ISO) standards for a database Call Level Interface (CLI). ODBC supports access to any database for which an ODBC driver is available.

ordered set

A set of members returned in some specific order. The ORDER function in an MDX query returns an ordered set. For more information about the ORDER function, see the OLE DB documentation.

parent

A member in the next higher level in a hierarchy that is directly related to the current member. The parent value is usually a consolidation of the values of all of its children. For example, in a Time dimension containing the levels Quarter, Month, and Day, Qtr1 is the parent of January. See also ancestor, child, descendant, sibling.

partition

One of the storage containers for data and aggregations of a cube. Every cube contains one or more partitions. For a cube with multiple partitions, each partition can be stored separately in a different physical location. Each partition can be based on a different data source. Partitions are not visible to users; the cube appears to be a single object.

pass-through statement

A SELECT statement that is passed directly to the source database without modification or delay. In PivotTable Service, the PASSTHROUGH option is part of the INSERT INTO statement. See also PivotTable Service.

pivot

To rotate rows to columns, and vice versa, in a crosstabular data browser. Also refers to choosing dimensions from the set of available dimensions in a multidimensional data structure for display in the rows and columns of a crosstabular structure.

PivotTable Service

An in-process desktop OLAP server that communicates with the OLAP server and provides interfaces for use by client applications accessing OLAP data on the server. PivotTable Service is an OLE DB for OLAP provider. It provides online and offline data analysis functionality.

populate

See process.

precalculate

To compute combinations of data while a cube is being processed. Data is precalculated in anticipation of ad-hoc queries to minimize computation and disk access time when a query is submitted. For example, total quantity sold for a year can be precalculated from individual sales transactions during cube processing. See also aggregation.

primary dimension table

A dimension table in a snowflake schema in a data warehouse that is directly related to the fact table. Additional tables that complete the dimension definition are joined to the primary dimension table instead of to the fact table. See also snowflake schema, dimension table.

private dimension

A dimension created for and used by a specific cube. Unlike shared dimensions, private dimensions are available only to the cube in which they are created. See also shared dimension.

process

In a cube, the series of operations that rebuilds the cube’s structure, loads data into a multidimensional structure, calculates summaries, and saves the precalculated aggregations. As a verb, to populate a cube with data and aggregations. One of three processing options for a cube.

In a dimension, the operation that loads data from a dimension table in a data warehouse into the levels defined for a dimension and rebuilds the structure of the dimension. One of two processing options for a dimension.

See also incremental update, refresh data.

provider

An OLE DB provider. An in-process DLL that provides access to a database.

record

See row.

refresh data

The series of operations that clears data from a cube, loads the cube with new data from the data warehouse, and calculates aggregations. Refresh data is used when a cube's underlying data in the data warehouse has changed but the cube's structure and aggregation definitions remain the same. One of three processing options for a cube. See also process, incremental update.

relational database

A collection of information organized in tables that can be queried by using data in specified columns of one table to find additional related data in another table. Tables of a relational database are independent of the methods used by a database management system to access and manipulate records. A relational database supports SQL.

repository

The storage container for the metadata managed by Decision Support Objects (DSO). Metadata is stored in tables in a relational database and is used to define the parameters and properties of OLAP server objects. See also metadata.

relational OLAP

See ROLAP.

ROLAP (relational OLAP)

A storage mode that uses tables in a relational database to store multidimensional structures. See also HOLAP, MOLAP.

role

The relationship between access rights and Microsoft Windows NT groups and users. OLAP Services uses roles to manage the sets of users who can access cubes and the manner in which they access them.

rollback

The act of removing partially completed transactions after a database or other system failure. See also commit.

rotate

See pivot.

row

A data structure that is a collection of elements (columns), each with its own name and type. A row can be accessed as a collective unit of elements, or the elements can be accessed individually. A row is equivalent to a record. See also column.

sample data

Artificially-generated data presented in lieu of actual data when a cube is queried before it has been processed. Sample data enables you to view the effects of structure changes while modifying a cube.

schema

A description of multidimensional objects such as cubes, dimensions, and so forth.

server

An application, usually running on a dedicated computer, that provides resources or data to client workstations on a network. See also OLAP server.

shared dimension

A dimension created within a database that can be used by any cube in the database. See also private dimension.

sibling

A member in a dimension hierarchy that is a child of the same parent as a specified member. For example, in a Time dimension with Year and Month levels, the members January 1997 and February 1997 are siblings. See also ancestor, child, descendant, parent.

slice

A subset of the data in a cube, specified by limiting one or more dimensions by members of the dimension. For example, facts for a particular year constitute a slice of multiyear data.

snap-in

A program that runs within Microsoft Management Console (MMC) and provides specific added functionality. The OLAP Manager is a snap-in.

See also OLAP Manager, Microsoft Management Console.

snowflake schema

An extension of a star schema such that one or more dimensions are defined by multiple tables. In a snowflake schema, only primary dimension tables are joined to the fact table. Additional dimension tables are joined to primary dimension tables. See also star schema.

sparsity

The relative percentage of a multidimensional structure's cells that do not contain data. OLAP Services stores only cells that contain data. A sparse cube requires less storage than a dense cube of identical structure design. See also data explosion, density.

star schema

A relational database structure in which data is maintained in a single fact table at the center of the schema with additional dimension data stored in dimension tables. Each dimension table is directly related to the fact table by a key column. See also snowflake schema.

table

See fact table, dimension table.

time dimension

A dimension that breaks time down into levels such as Year, Quarter, Month, Day. In OLAP Services, a special type of dimension created from a date/time column.

transaction

A group of database operations combined into a logical unit of work that is either wholly committed or rolled back. A transaction is atomic, consistent, isolated, and durable.

tuple

An ordered collection of members from different dimensions. For example, (Boston, [1995]) is a tuple formed by members of two dimensions: Geography and Time. A single member is a degenerated case of a tuple and can be used as an expression without the parentheses. See also axis.

For more information about tuples, see the OLE DB documentation.

value expression

A multidimensional expression (MDX) that returns a value. Value expressions can operate on sets, tuples, members, levels, numbers, or strings. For example, set value expressions operate on member, tuple, and set elements to yield other sets. For more information about MDX expressions, see the OLE DB documentation.

virtual cube

A logical cube composed of dimensions and measures of one or more physical cubes, Virtual cubes are similar to views in a relational database. Virtual cubes combine data from the underlying physical cubes and require no additional data storage.

virtual dimension

A logical dimension based on the properties of members of a physical dimension. Members of a virtual dimension are derived from the values of one of the properties of a member of the physical dimension. For example, a virtual dimension Color could be derived from a product dimension containing member properties Color, Size, and Style; it could contain members Blue, Red, and Green, which are values for the property Color. See also dimension, member, member property.

write-back

The facility that enables users to apply changes to data in a cube. User-inititated changes to cube data are logged to a separate partition table associated with the cube and applied automatically as cube data is viewed. To the user it appears as if the data in the cube has changed.

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