The routines for data mart administration are implemented in the Informix server to run on their own virtual processor, the DWA-VP. This DWA-VP normally gets started automatically as soon as the first administrative operation is performed. Most of these administration commands run so fast, that a single DWA-VP is sufficient to finish all operations without delay.
An exception to this is the loading of a data mart, which can take considerably longer, depending on the amount of data to be loaded. Moreover, the load processing keeps the DWA-VP so busy with transferring the data to IWA, that concurrent administration commands for different data marts can be noticeably delayed. For example a command to list the existing data marts while one data mart is being loaded, may get blocked by the ongoing data load, possibly even until the load has completed. Additionally, it is possible that the newly loaded data mart is listed with status "LoadInProgress", even though the load finished before the data mart listing is output to the user. From the point of view of the internal implementation this status may be correct, but for a user it is not really comprehensible, because at the time when the answer arrives this status is already obsolete. The status already has changed to "Active", because the data load finished in the meantime.
To avoid the delay of administrative commands in such situations, the Informix server administrator can manually start an additional DWA-VP. This is done with the following command:
onmode -p +1 dwavp
The same rules apply as for the other classes of virtual processors (VPs) that are started in this way. The above command starts the additional DWA-VP dynamically (i.e. immediately), but does not make it permanent in the configuration file of the Informix server. After a restart of the Informix server the command needs to be run again. If there should always be two DWA-VPs running, without the need to issue the above command, then the following line can be added to the configuration file of the Informix server:
For completeness it should be noted, that it is not sensible to run several administration commands concurrently for the same data mart.