A data processing mode determines how the DevExpress Dashboard performs data aggregation and filtering operations. There are two data processing modes:
- Server mode. Data-related operations are performed server side. When an end-user applies a filter to a dashboard item or groups data, the Dashboard composes a SELECT statement with the specific WHERE or GROUP BY clauses, and sends it to the server.
- Client mode. Data-related operations are performed on the workstation ( WinForms Dashboard Designer or Viewer) or web server side (Web Dashboard controls). The Dashboard loads a compressed snapshot of aggregated data into a workstation/web server memory. Data compression, proper data grouping, and multi-threading algorithms reduce memory consumption and improve data shaping operation performance.
For more information refer to the following topics:
Several considerations for selecting a mode for the SQL Data Source:
- With a large number of records, consider server data processing mode. The dashboard performs all calculations server side. When an end-user changes a filter, the dashboard requests data from a data base with new filter values.
- With a small number of records, it is better to switch to client mode. The dashboard requests all data from the database, caches it on the client side and performs the required calculations. When an end-user changes a filter or other parameters, the dashboard does not request data from the server and uses already received cached data.
- An application performance depends on multiple factors besides the data processing mode. Consider first the database structure and server workload, then decide which mode to choose.