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A datapoint is similar to a field in a table, but with built-in dimensional linkages. It also has linkages back to sources and forward to measures, which provide a clear lineage from harvest point to presentation.
There are four different types of datapoints in PMF:
To change a datapoint:
Note:
You can make an exact copy of any existing datapoint. After making the copy, you can immediately alter it as needed. To copy a datapoint:
All loaded data from a derived or generated datapoint can be wiped out or deleted in a single operation, because they are not attached to a source.
Note: Wiping data affects downstream datapoints for the datapoint you wipe. Every datapoint downstream is marked as having incomplete components. Incomplete components do not participate in recalculation.
Note: It may take PMF a moment to purge all of the data.
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Loadable Sources manage Loadable datapoints. You can drill into any datapoint on a Loadable Source to view the specifics about the datapoint, or you can access Loadable datapoints from the separate panel button for them.
The Edit Datapoint panel opens, as shown in the following image.
Note: Most of the information for a loadable datapoint is read-only.
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Derived datapoints let you create calculations that include dimensional metadata. For example, you can create a series of derived datapoints that perform a series of calculations on Sales performance for your manufacturing company:
These datapoints can now be added up to become Total Cost (by Product, Location and Time).
You can then set Total Cost against your Sales (by Product, Location and Time) to calculate Profit.
You can also load precalculated Total Costs and Profit datapoints from an external Source, but there is no guarantee the data will be calculated in the proper order. If you use derived datapoints to calculate the values:
Lineage Chains are currently available in the Lineage tabs on dimensions, sources, datapoints, and measures panels.
To create a derived datapoint:
The New Datapoint panel opens.
Calculations can also include constants. To add a constant, drag the Constant object into position on the canvas, and type in the constant value inside the Constant object.
Separate datapoints for WebFOCUS functions are typically created during the source load, since capturing these calculations is done best in the first-generation in the lineage, during harvesting.
For example, if you want to capture counts of a particular condition, rather than trying to save all those attributes somewhere so you can perform the filtering later, you can determine When, that is what filters should be true, for the count. You can then pull that count into a loadable datapoint. Approaching data this way allows you to make calculations in the lineage after this harvesting phase simpler for you to manage.
PMF allows you to create an unlimited number of calculations for your measures using special datapoints that store and process calculations, known as derived datapoints. These calculations can be based on one or more existing datapoints, of any kind, including loadable, user-entered, generated, and other derived datapoints. Note the following:
Recalculating a complex lineage chain through possibly hundreds of thousands or millions of row values can be an expensive operation, so you have full control over how much of this calculation is performed during normal processing hours.
Note: During scheduled load cycles, since PMF is less used during scheduled load times (usually overnight), recalculation can always go through the entire lineage.
You can preview the data that PMF will generate by clicking the Preview tab, as shown in the following image.
The Preview tab generally shows rows that are new, or will be updated or deleted.
Tips:
Derived datapoints can have a complex, multi-part lineage, depending on their relationship to other derived datapoints.
You can view lineage for all datapoints for any derived datapoint. Lineage shows the progress of data through PMF, from the external data harvested into datapoints, through any derived datapoints, and finally all terminal points in Measures. The Lineage tab displays the components in the generated source by default, as shown in the following image.
You can click on any node to expand it and display the contribution of that node to the lineage. You can also click Expand All or Collapse All to display or hide the entire lineage, as shown in the following image.
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Generated datapoints enable PMF to create sample data for your models. With generated datapoints, you can:
Generated datapoints are designed for the following situations:
Important: Generated data should never be treated as real performance data. PMF 5.3.2 does not yet mark generated data as “unreal,” so use generated datapoints only for non-production work.
To create a generated datapoint:
The New Datapoint panel opens.
Setting dimensions affects some options on the Rules tab, so if you know the dimensions you want to use for generating, set them first.
Specifies the decimal format of the data generated:
Examples of typical decimal formats are: D12.2, I8, D20.6 and, I32.
Controls how PMF will calculate the sample values:
The lowest and highest number for the range of possible values PMF will generate. The numbers will be formatted using the mask you entered in the Decimal Format field.
Controls the amount of data PMF generates by letting you focus the data on dimensional choices:
You can specify any datapoint to train from a loadable datapoint, user-entered datapoint, derived datapoint, or another generated datapoint.
This option should remain enabled, unless you have a very large data mart and want to reserve recalculation for overnight or other offline processing.
Note: This option enabled by default. To disable it, see Load Settings.
A description of the datapoint.
Tips:
Generated Datapoints are primary sources for data in PMF. They are treated as first generation in any lineage, along with loadable datapoints and user-entered datapoints.
Generated datapoints are used when you lack real data to prove that your model works, or they are needed for a demonstration. Once you are ready to use a working model with real data, generated datapoints are no longer necessary to feed your metrics.
To promote the generated datapoint:
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