Feature Representation

Features read from PostGIS raster consist of a series of attribute values and geometry. The feature type of each feature is as defined on its DEF line.

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 topic.

Attribute Name

Contents

postgis_type

The type of geometric entity stored within the feature. This will either be postgis_raster or, in the case of a null value in the raster column, postgis_none.

postgres_oid

Tables in a PostgreSQL database may be created with an OID column, although this is typically used only by system tables.

This attribute is present and set to the value of the OID column if it is present in the table being read.

Features read from, or written to, PostGIS also 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.

No Coordinates

postgis_type: postgis_none

Features with no coordinates are tagged with this value when reading from PostGIS. Note that when reading or writing attribute-only data tables, the PostgreSQL reader/writer should be used instead. Note also that this is not a valid OGC type.

Raster

postgis_type: postgis_raster

Features tagged with this value consist of a raster.