All dimension sources which have an aggregate content at a specified level need to contain the column that is the primary key of that level. When that is the case, specify the key that is the primary key of that level. The dimension table logical key has to be associated with the lowest level of a dimension and has to be the level key for that level.Ī logical level can have multiple level keys. The level key defines the unique elements in each logical level. Each logical level (except the topmost level defined as a Grand Total level) must have one or more attributes that compose a level key. Rather, logical hierarchies exist implicitly through the relationships between levels. In the Business Model and Mapping layer, logical hierarchies are not defined as independent metadata objects, unlike hierarchies in the Presentation layer. Day has two named parent levels called Fiscal Year and Calendar Year, which are both children of the All root level. All hierarchies must have a common leaf level and a common root (all) level.įor example, a time dimension might contain a fiscal hierarchy and a calendar hierarchy, with a common leaf level of Day. Each dimension contains one or more hierarchies. All logical columns in the same dimension table have to be associated with the same dimension. Any column that you do not associate with a logical level is automatically associated with the lowest level in the dimension that corresponds to that dimension table. However, it is not necessary to explicitly associate all of the columns from a table with logical levels. All levels, except the Grand Total level, need to have at least one column. The aggregation level for those measures will always be the grand total for the dimension.
However, you can associate measures with a Grand Total level. A Grand Total level does not contain dimensional attributes and does not have a level key. Each dimension can have just one Grand Total level. A special level representing the grand total for a dimension. The following are the parts of a dimension: The recommended sequence for creating logical levels is to create a Grand Total level and then create child levels, working down to the lowest level. This chapter contains the following topics:Ĭreating and Managing Dimensions with Level-Based HierarchiesĬreating and Managing Dimensions with Parent-Child HierarchiesĪ dimension contains two or more logical levels. Oracle BI Answers supports drill-down on these hierarchical columns.
Note that you can also expose dimension hierarchies by adding one or more columns from each hierarchy level to a subject area in the Presentation layer. See "Working with Presentation Hierarchies and Levels" for more information. Creating hierarchies in the Presentation layer enables users to create hierarchy-based queries. You can expose logical dimensions to Oracle BI Answers users by creating presentation hierarchy objects that are based on particular logical dimensions. Additionally, each cube in the data source should have at least one dimension and one measure in the Business Model and Mapping layer.
A dimension is specific to a particular multidimensional data source (it cannot be used by more than one) and cannot be created and manipulated individually. For example, you do not create dimension level keys.
#GIDEROS GET LOGICAL DIMENSIONS SERIES#
Oracle Business Intelligence also supports a special type of level-based dimension, called a time dimension, that provides special functionality for modeling time series data.īecause dimensions for multidimensional data sources are defined in the source, they do not require as much work compared with dimensions in other data sources. In parent-child hierarchies, members all have the same type. Level-based hierarchies are those in which members are of several types, and members of the same type occur only at a single level. There are two types of logical dimensions: dimensions with level-based hierarchies (structure hierarchies), and dimensions with parent-child hierarchies (value hierarchies). It also provide the metadata that the Oracle BI Server uses to drill into and across dimensions to get more detailed views of the data. This structure represents the organization rules and reporting needs required by your business. In each dimension, you organize logical columns into the structure of the hierarchy. Note that dimensions exist in the Business Model and Mapping (logical) layer and in the Presentation layer. Common dimensions might be time periods, products, markets, customers, suppliers, promotion conditions, raw materials, manufacturing plants, transportation methods, media types, and time of day.
One or more logical dimension tables can be associated with at most one dimension object. In the Business Model and Mapping layer, a dimension object represents a hierarchical organization of logical columns (attributes).
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