Feature Representation
Features read from DynamoDB consist of a series of attribute values only – no geometry. The feature type of each feature is as defined on its DEF line but the only type used is dynamodb_none.
Features written to the database have the destination table as their feature type, and attributes as defined on the DEF line.
In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this section.
Attribute Name |
Contents |
dynamodb_type |
The type of geometric entity stored within the feature. The valid values for the object model are listed below: dynamodb_none |
Features read from, or written to, DynamoDB have an attribute for each column in the database table. The feature attribute name will be the same as the source or destination column name. The attribute and column names are case-sensitive.
Binary types are supported within DynamoDB. When writing, these will be written out as the raw bytes present on any attribute declared a binary type on the feature type’s schema.
Set types in DynamoDB are represented as JSON strings within FME. Note that DynamoDB does not support empty sets, nor empty elements within sets. For example, the following JSON-formatted string stored in an attribute named numbers containing the number set {2,4} is represented as:
{ “numbers” : [ 2, 4 ] }
Binary sets and string sets use the same JSON representation, but the elements of the JSON array of a binary set should be written as the hex encoded string representations of the underlying binary blobs.
No Coordinates
dynamodb_type: dynamodb_none
Features with no coordinates are tagged with this value when reading or writing to or from DynamoDB. This is the only type of a DynamoDB feature.