To access feature type format parameters, open the Feature Type Properties dialog by clicking the properties 
button on a feature type in the workspace.
These parameters apply only to a selected feature type, not to the entire reader.
Note: If a feature type parameter corresponds to a reader-level parameter, then the reader parameter will be ignored and the feature type parameter will be used.
WHERE Clause
Optional. This parameter constitutes the WHERE clause of the SQL query to execute against the Document Collection. The value is passed as-is, with no validation.
If not specified, all Documents in the Collection are read.
Note: All property (column) names must be prefixed with root. For example, to filter on the id property, the WHERE clause must be root.id = ‘foo’, not id = ‘foo’.
For details on how to build WHERE clauses for DocumentDB, see https://azure.microsoft.com/en-us/documentation/articles/documentdb-sql-query/#where-clause.
Document Options
Geometry Property
Optional. If the specified property exists on a Document, and its value is GeoJSON, the DocumentDB Reader will parse the GeoJSON and include it as geometry on output features .
Default: geom