MDX Glossary
( Empty )
Represents a null value or the absence of data in a cell. MDX treats empty cells as zero in many numeric calculations.
All Member
A special member that represents the aggregation of all other members within a dimension or a level. It is typically used to display totals or aggregates across the entire dimension.
Axis
In MDX, axes define the structure of a query result set. Typically, the ROWS and COLUMNS axes are used to display measures and dimensions. Other axes like SLICERS can be used for filtering.
SELECT
{[Measures].[Sales Amount]} ON COLUMNS,
{[Product].[Category].MEMBERS} ON ROWS
FROM
[Adventure Works]Cell
The intersection of members from each dimension in a cube. Each cell contains a value (typically a measure) and can be accessed and manipulated by MDX.
Cube
A multidimensional data structure that organizes data into measures and dimensions, allowing for analysis and reporting. Cubes are the primary data source for MDX queries.
Default Member
The member that is automatically selected for a dimension when it is not explicitly referenced in a query. This member is used to define the context for calculations.
Dimension
A hierarchical structure that categorizes data, such as Time, Geography, or Product. Dimensions provide the context for measures.
Hierarchical Member
A member within a dimension that has a parent-child relationship with other members. Hierarchies allow for drilling down and rolling up data.
Level
A layer within a dimension's hierarchy. For example, a Time dimension might have levels for Year, Quarter, Month, and Day.
Measure
A numeric value that can be aggregated and analyzed. Examples include Sales Amount, Quantity Sold, or Profit.
Member
An element within a dimension or a level. For example, "2023" is a member of the Year level, and "Bikes" is a member of the Category level.
MDX (Multidimensional Expressions)
A query language used to retrieve data from multidimensional data sources, such as SQL Server Analysis Services cubes.
Non-Empty
A keyword used in MDX queries to exclude rows or columns that contain only empty cells. This can significantly reduce the size of the result set.
SELECT
NON EMPTY {[Measures].[Sales Amount]} ON COLUMNS
FROM
[Adventure Works]Set
An ordered collection of members. Sets are fundamental to MDX operations and are used to define axes, filter data, and perform calculations.
Tuple
An ordered collection of members, one from each of the required dimensions. A tuple represents a specific point in the multidimensional data space.
([Product].[Category].&[Bikes], [Date].[Calendar Year].&[2023])