Configuring a Data Source in Xpress Insight to Expose Data to Tableau

An alternative approach is to define a data source within Xpress Insight and to then pull that into the Tableau workbook. Each companion file data source definition contains one or more mirror table references, each of which refers to one of the configured mirror tables in the companion file. The following companion file fragment shows an extension of the previous mirror table example with three data sources defined:

<database-mirror table-prefix="facility_">
  <mirror-tables>
    <mirror-table name="clients">
      <entity name="CLIENT_LATITUDE"/>
      <entity name="CLIENT_LONGITUDE"/>
      <entity name="DEM"/>
    </mirror-table>
    <mirror-table name="depots">
      <entity name="DEPOT_LONGITUDE"/>
      <entity name="DEPOT_LONGITUDE"/>
      <entity name="CAP"/>
    </mirror-table>
    <mirror-table name="driving">
      <entity name="DRIVING_DISTANCE">
      <entity name="DRIVING_TIME">
    </mirror-table>
  </mirror-tables>
  <data-sources>
    <data-source name="clients_datasource">
      <mirror-table-ref name="clients"/>
    </data-source>
    <data-source name="depots_datasource">
      <mirror-table-ref name="depots"/>
    </data-source>
    <data-source name="driving_datasource">
      <mirror-table-ref name="clients "/>
      <mirror-table-ref name="depots"/>
      <mirror-table-ref name="driving "/>
    </data-source>
  </data-sources>
</database-mirror>

Xpress Insight uses the datasource definition to generate and publish a Tableau data source. Joins are generated between the specified tables and also with the insight_scenarios, insight_projects and insight_security tables. The generated data source also includes a filter to ensure users only have access to data in scenarios for which they are authorized.

Note When a workbook is subsequently created in Tableau, it can be configured to refer to a datasource from the companion file. The data source will be named using the defined name prefixed with the table-prefix. For the example above, facility_clients_datasource.

Note If a workbook contains its own embedded data source then it will be used in preference to any data source defined in the companion file.

Note Data source definitions are only supported in companion file version 3.0 or later and for use with Tableau 9.3 or later if supported.

When creating a Tableau datasource using a companion file data source definition, Xpress Insight joins the mirror tables using the following rules:

1. A mirror table containing one or more scalars is joined to other mirror tables using the scenario_id column.
2. A mirror table containing a set can only be joined to a mirror table containing one or more scalars by the scenario_id column. A mirror table containing a set cannot be joined to other mirror tables which contain a set or arrays.
3. A mirror table containing one or more arrays can be joined to a mirror table containing one or more scalars by scenario id. It can also be joined to mirror tables containing arrays if they have one or more index sets in common. In this case the tables will be joined by the largest common subset of their index sets.
4. In all cases the mirror tables will be joined to insight_scenarios, insight_projects and insight_security via their scenario_id column.

   Note Data source definitions are processed when an app is imported or updated in Xpress Insight. If any of the data source definitions are invalid then an error will be displayed and the operation will be aborted.