Index | Prev | Next

rdb-RdbArchiveHistoryProvider

When installed and configured to reference an existing RDBMS device that has already exported local history data to a remote relational database using Niagara’s standard RdbmsHistoryExport descriptors, this component supplements history time queries with archived history records retrieved back (on-demand) from the remote RDBMS.

This provider is in the rdb module’s palette. To add it to your station, expand HistoryService Archive Provider in the palette and drag this component to the Config > Services > HistoryService in the Nav tree.

Figure 34.   Rdb Archive History Provider properties
Image

To access this Property Sheet, expand Config > Services > HistoryService > Archive History Providers and double-click RdbArchiveHistoryProvider.

In addition to the standard properties (Status, Enabled, and Fault Cause), these properties configure the archive history provider.

Property Value Description
Max Archive Results Per Query number (defaults to 50,000) Determines the maximum number of history records to read from the RDBMS for any history time range query that taps into it. If more history records are available beyond this limit at history query time, the Archive Limit Notifications property defines the behavior of a subset of Workbench views but not all of them. When the limit is reached for a query, in addition to the warning, you get truncated archive history results that always consider the most recent history records first.

Web chart and HTML5 History Table views (accessible from a browser and Workbench) provide their own notification when a history query exceeds this limit.

Archive Limit Notifications drop-down list (defaults to Notify Once Per Query Range Per Session) Specifies the Workbench notification behavior when the Max Archive Results Per Query limit is exceeded for a history query made from a Workbench user connected to the station.
 NOTE: This property does not apply to HTML5 history views including HTML5 views accessed within Workbench, such as the Web Chart view. It only applies to native Workbench views that perform history queries, such as the AX History Chart or AX History Table views. 

Notify Once Per Query Range Per Session limits the frequency of warnings to once per history query range per session. This setting attempts to balance providing notifications while reducing too much spam.

Never Notify Turns notification off completely.

Always Notify displays a warning every time a history query's results exceed the Max Archive Results Per Query limit.

Ord To Rdbms ORD with choosers References the RDBMS device instance in the local station from which to retrieve archive history data on demand.
Use Default Fetch Size true (default) or false It is not common to change this property from the default value. In rare cases, it may be necessary to tweak the fetch size for retrieving history records from a connection to the RDBMS for performance reasons.

true, uses the default fetch size specified by the referenced RDBMS device when making a connection to retrieve history data from the RDBMS.

false uses the Custom Fetch Size value instead.

Custom Fetch Size number It is not common to change this property from the default value. In rare cases, it may be necessary to tweak the fetch size for retrieving history records from a connection to the RDBMS for performance reasons. This property can specify a custom fetch size to use when making a connection to retrieve history data from the RDBMS. This property value applies only when the Use Default Fetch Size property is set to false.
Fetch Size To Use read-only, A value of zero is acceptable (and common). Based on the current value of the Use Default Fetch Size and Custom Fetch Size properties, this property indicates the current fetch size in use for any connections made to the configured RDBMS when retrieving archived history data.

Related Links

  • rdb database modules (Parent Topic)

    • Index | Prev | Next