Setting the Cache Usage Mode
In the Query Properties dialog in the query monitor, you can select a cache usage mode. This option is intended for use by experts. It allows you to define when cache entries can be used to answer a query, and when the data has to be read again.
Prerequisites
To be able to change the cache usage mode, you first need to deselect the InfoProvider Setting flag for the cache mode and to select a cache mode other than I: Cache is inactive.
For queries on an aggregation level, it is not possible to set a data integrity profile, cache mode or cache usage mode.
Context
To be able to use the cache usage modes correctly, you have to consider dependencies between data integrity and data stability on the one hand, and query performance on the other:
If you always want to see the current data, you can deactivate the cache (cache mode I - cache is inactive). The data is then not written to the cache and is always read anew. This option is very performance intensive. Using this option can also produce inconsistent results if the database needs to be accessed more than once in order to create the result, and the underlying data changes between one database access and the next.
If you want to have completely consistent navigation, you can select the read mode Query to Read All Data at Once (A). With this option, all data is read into the query cache when the query starts. All further navigation steps can be processed using the query cache. This option is also very performance intensive.
If you want to have the best possible level of query performance, the cache usage mode opens a happy medium between these two options: The purpose of this is to update as little data as infrequently as possible, to use the cache as often as possible instead and thus to achieve the best possible query performance. The cache usage mode uses the InfoProvider functionalities to provide information about the fill status and to read old data versions, while trying to return a consistent result.
If you set the cache mode to "P", multiple InfoProviders with different cache usage modes can be used in the query.