Caching

In QMF, caching is a feature that allows you to accelerate the application performance, but affects the relevance of the data.

You can configure the caching functionality for the following entities:

  • Repositories

  • Queries

  • Data sources

  • Virtual data sources

  • Visual dashboards and visual reports

Repository cache
When caching is configured for a repository, the application saves the contents of that repository, including all the objects and metadata, in the local memory of your computer or on the web server. Repository cache is cleared when the time limit is exceeded.

Repository cache is also cleared when you exit the application. Caches of other QMF entities are not cleared when you exit the application.

Query cache
When caching is configured for a query, the results of that query are saved in cache after its first run. Later, if the query is run again unchanged, the results are retrieved from cache. Query cache is cleared when the time limit is exceeded.
Data source cache
When caching is configured for a data source, data from the tables in that data source is saved in cache, so that users can work with it without directly accessing the database. Data source cache is available for relational data sources only. The cache is cleared when the time limit is exceeded.
Virtual data source cache
When caching is configured for a virtual data source, records from the tables in that data source are saved in cache, so that users can work with the contents of the tables without directly accessing the database. Virtual data source cache is cleared when the time limit is exceeded and can be updated regularly. You can configure the application to update the cache of virtual data sources automatically in two distinct ways:
  • Expired cache can be updated when the user tries to run a query against the outdated data. This is the default option for QMF for Workstation, although it can be re-configured.
  • Expired cache can be updated regularly, according to the schedule. This is the default option for QMF for WebSphere┬«, although it can be re-configured.
Visual dashboard cache and visual report cache
When caching is configured for a visual dashboard or a visual report, cache stores the results of the queries that provide data for that visual dashboard or visual report. This allows the dashboard or report to function faster, but affects the relevance of the data. Visual dashboards and visual reports cache is cleared when the time limit is exceeded.

QMF allows users to automate the update and expiration of virtual data source cache and visual dashboard cache by using schedules.