Work Modes

To minimize the overhead of sending response messages from the database to the client, the Direct Read feature allows historical data to be read directly from the database, thereby avoiding the message-based overhead. This chapter describes "Direct Read".

To minimize overhead for sending response messages from the database to the client, the Direct Read feature allows historical data to be read directly from the database, thereby avoiding the message-based overhead. If the direct read operation is faster than a non-direct read depends on multiple parameters, e.g. the size of the answer and the location of the reading client (local/remote). This function can only be used when backends are loaded in-proc. In this mode, the following calls must be ignored:

• requestMetadataDeltaSynchronously (see Elements)
• requestRedundancyInfoSynchronously (see Redundancy state)
• requestValuesNewerThan and requestCurrentAlerts (see Last values)
• onWriteRequest (see Write handler).