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If you call up a buffer object in the OLAP cache monitor, the system displays information about the structure elements of the database cache.

From a logical viewpoint, the database cache is structured as a hierarchy. This corresponds to  Hierarchical Display. For every query request, a directory is displayed in an extensive query directory that maps the structure elements of the cache on a total of three levels.

From a physical viewpoint, all elements in the cache are stored in a flat structure. Their sequence reflects the order in which they were created.

The following table offers an overview of the logical structuring of information in the OLAP cache monitor according to the memory ID in the hierachical display, and the corresponding structure element:

Mapping between memory IDs and structure elements of the cache

Memory ID

Structure element

Meaning

Query name (technical name)

QUERY

Table with queries in the cache (directory)

Hierarchies / variables

VAR/SH

Complex structure for variables in fixed filters and display hierarchies that have been requested for the query

Selection / data

FF

Complex structure for the entire selection for the query

SP

Storage table: data package, a sequence of bytes

Note

By double-clicking on the Detail Display dialog box at the Query Name and Hierarchies/Variables level, you can display more statistical values and information about variables and hierarchies.

Like the query name itself, these details belong to the key for the cache.

Caution

If no data is loaded from the cachem this is often due to the variable assignment. You can use the Detailed Display for Hierarchies / Variables to check this:

If variables are part of a fixed filter and therefore cannot be changed for query navigation, and are filled differently in each case (by manual input or user-defined variables), the cache for the query has to regenerated every time.

We therefore recommend that you make variables for query navigation changeable. In this way you can achieve the highest possible level of reusability for the cache.

The following graphic shows the relationship between the different OLAP cache structure elements.

Buffer Object Display in OLAP Cache Monitor

Column

Meaning

Memory ID

Cache structure element ID

Changed

 

GUID

 

Parent memory ID

Cache structure element ID that is logically on the next highest hierarchy level 

Parent GUID

Internal logical ID of parent element

Information

 

Persistence mode

 

Bytes

Cache structure element size in bytes

Bytes aggregated

 

You can flag an entry for deletion in the context menu. See Cache Parameters.