1.1 Glossary

This document uses the following terms:

allow axis: When Dimension Security is enabled, it is the set of tuples which are allowed on the axis, based on the current user's security permissions.

B-level: A level automatically created in a hierarchy that is not defined as part of the permanently stored hierarchy metadata. An end user creates it by utilizing a custom grouping feature.

cache ratio: The ratio of members within a particular subhierarchy of a dimension. This allows the SONAR algorithm to optimally distribute computation between the client and the server.

calculation pass: A stage of calculation in a multidimensional cube in which applicable calculations are evaluated. Multiple passes might be required to complete all calculations.

cell writeback: Refers to an OLAP feature in which the client can define calculations that are written back to the server.

commit version: Within a transaction, there can be multiple times that changes are committed to the database. Each time such an internal commit operation is performed, the commit version is incremented.

Component Object Model (COM): An object-oriented programming model that defines how objects interact within a single process or between processes. In COM, clients have access to an object through interfaces implemented on the object. For more information, see [MS-DCOM].

cube: A set of data that is organized and summarized into a multidimensional structure that is defined by a set of dimensions and measures.

custom member formula: An expression associated with a dimension member that defines how the cell value at this member is to be calculated.

custom rollup: An aggregation calculation that is customized for a dimension level, dimension member, or measure. A custom rollup contains a custom formula or operator, overrides the aggregate functions of a cube's measures, and is defined on a hierarchy.

data definition language (DDL): A subset of SQL or XMLA statements that defines all the attributes and properties of a database and its objects. DDL statements typically begin with CREATE, ALTER, or DROP.

data member: A child member associated with a parent member in a parent-child hierarchy. A data member contains the data value for its parent member, rather than the aggregated value for its children.

Decision Support Objects (DSO): A programming language provided to define OLAP objects, such as cubes and dimensions.

dimension: A structural attribute of a cube, which is an organized hierarchy of categories (levels) that describe data in the fact table.

dimension writeback: Refers to the capability where a client can perform an operation that modifies a dimension's structure on the server, for example, by adding or deleting members on the dimension.

drillthrough: The OLAP capability to go beyond browsing the data in a cube and to drill into the original data store.

fact table: A central table in a data warehouse schema that contains numerical measures and keys relating facts to dimension tables. Fact tables contain data that describes specific events within a business, such as bank transactions or product sales.

flags: A set of values used to configure or report options or settings.

flexible dimension: A dimension in which vertices and subtrees can be flexibly moved around during an incremental update operation. If a dimension is not flexible and needs to have members moved around, it has to be processed in a full processing operation, not in an incremental processing operation.

handshake: An initial negotiation between a peer and an authenticator that establishes the parameters of their transactions.

hierarchy: A logical tree structure that organizes the members of a dimension such that each member has one parent member and zero or more child members.

linked cube: A cube based on a cube defined on another OLAP server.

master dimension name: For a virtual dimension, this is the dimension upon which it is based.

master level name: For a level within a virtual dimension, this is the level upon which it is based.

master property name: For a virtual dimension, this is the property upon which it is based.

measure: In a cube, a set of values that are typically numeric and are based on a column in the fact table of the cube. Measures are the central values that are aggregated and analyzed.

measure group: A collection of related measures in a cube that derive from a single fact table, typically in a data source view.

member: A single master data record that is stored in the Master Data Services (MDS) system.

member key: The property of a member that specifies the identifier used for that member. The value of this property can specify either a cell that contains the identifier or an expression that evaluates to the identifier.

member name: The property of a member that specifies the name of the member. The value of this property can specify a cell that contains the name or an expression that evaluates to the name.

member qualified name: A member name, with some qualifiers added to it. However, even with qualifiers, it is not guaranteed to be unique.

member unique name: A member name, with qualifiers added, such that is guaranteed to be unique within a cube.

Multidimensional Expressions (MDX): A syntax that is used for defining multidimensional objects, and for querying and manipulating multidimensional data.

named set: A grouping of dimension members or items from a data source or a set expression that is named and treated as a single unit and that can be referenced or reused multiple times.

nonleaf: In a tree structure, an element that has one or more subordinate elements. It can be a dimension member that has one or more descendants or, in indexes, an intermediate index node that points to other intermediate nodes or leaf nodes.

Ntab: An internal structure, stored in either client or server memory, which allows mapping of a PATH to a member object that contains information about the member.

object: A set of attributes, each with its associated values. For more information on objects, see [MS-ADTS] section 1 or [MS-DRSR] section 1.

Online Analytical Processing (OLAP): A technology that uses multidimensional structures to provide access to data for analysis. The source data for OLAP is stored in data warehouses in a relational database. See also cube.

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.

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.

ragged hierarchy: An unbalanced hierarchy.

real-time OLAP operation: It is usual that OLAP cubes are processed periodically, and so there is a time lag between data updates in the source store and the OLAP cube. With real-time OLAP, the cube is updated immediately whenever source data changes in the source data store.

rigid dimension: A dimension in which members cannot change position within the dimension's hierarchy during an incremental processing operation. If a member has to change its position in the hierarchy, it would require a full reprocessing of the dimension.

rowset: The OLE DB object that is used to contain a result set. It also exhibits cursor behavior depending on the rowset properties set by an application.

SET: An ordered set of tuples with the same dimensionality.

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.

solve order: The order of evaluation (from highest to lowest solve order) and calculation (from lowest to highest solve order) for calculated members, custom members, custom rollup formulas, and calculated cells in a single calculation pass of a multidimensional cube. Solve order is used to determine formula precedence when calculating values for cells in multidimensional cubes, but only within a single calculation pass.

SONAR: An algorithm used to divide computation of query results between the client and server in the most optimal way.

Stateful Visual Total: A displayed, aggregated cell value for a dimension member that is consistent with the displayed cell values for its displayed children. The visual total of a cell can vary from the actual total if some children of the cell are hidden.

Transmission Control Protocol (TCP): A protocol used with the Internet Protocol (IP) to send data in the form of message units between computers over the Internet. TCP handles keeping track of the individual units of data (called packets) that a message is divided into for efficient routing through the Internet.

tuple: An ordered grouping of members from different dimensions or hierarchies. A single member is a special case of a tuple and can be used as an expression. Every hierarchy does not have to be represented in a tuple.

type A hole: Holes can occur in a dimension when a member's parent is not on the level directly above the member. A type A hole is where the hole is in the middle of the dimension structure (as opposed to at the leaf or at a point where all descendants are also holes, or as opposed to the case of a user-defined grouping level).

unary operator: A property associated with a dimension member that controls how the member is to be aggregated. The unary operator overrides the defined aggregation function for the measure.

unbalanced hierarchy: A hierarchy in which one or more levels do not contain members in one or more branches of the hierarchy. This is also known as a ragged hierarchy.

Unicode: A character encoding standard developed by the Unicode Consortium that represents almost all of the written languages of the world. The Unicode standard [UNICODE5.0.0/2007] provides three forms (UTF-8, UTF-16, and UTF-32) and seven schemes (UTF-8, UTF-16, UTF-16 BE, UTF-16 LE, UTF-32, UTF-32 LE, and UTF-32 BE).

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.