Backfill or recalculate data for an analysis

PI Analysis Service 2016 R2 introduced recalculation capabilities for expression, rollup and SQC analyses. Data Archive storing the output PI points must be running version 2016 R2 or later. Beginning with PI Analysis Service 2018, you can opt for recalculation of all dependent analyses. An analysis whose input comes from an output of another analysis is considered dependent.

1. In the Elements browser, select an element, and click the Analyses tab to see the analyses defined for the element.

2. From the list of analyses, right-click the running analysis that you want to use to backfill or recalculate data, and click Backfill/Recalculate.

3. In the Backfilling or recalculation for analysis name window, perform the following actions.

   1. In the Start Time and End Time fields, specify the time period for which you want to backfill missing data while retaining existing data, or delete and recalculate data. You can use standard PI time expressions or click to select a specific date period.

   2. Decide how existing data should be treated. For an expression, rollup or SQC analysis that outputs to an attribute:

      • To ensure that existing data is retained and only missing data is backfilled, select Leave existing data and fill in gaps.

      • If input data or analysis algorithms have changed and you want to delete existing output data, select Permanently delete existing data and recalculate.

      • Optional. Check the box next to Recalculate dependent analyses to queue all dependent analyses for manual recalculation.

        Note: Selecting this option may cause recalculation to occur multiple times for dependent analyses. The recalculation time range for dependent analyses may be different than the time range you selected when queuing recalculation. For more information, see note at the end of step 7 in Backfill or recalculate data for multiple analyses.

   Note: Event frames are automatically deleted and recalculated for event frame generation analyses. Be aware that information such as annotations, acknowledgments, reason codes on those event frames will be lost.

4. Click Start to start the backfill or recalculation.

5. For details on the backfill or recalculation status or to cancel, right-click the analysis and click Backfill/Recalculate Status.

Video

For information on how to backfill or recalculate data for an analysis, watch this video: