generate-mapping crash with Oracle OE sample schema

[cygri]

Oracle ships with a sample schema called OE (order_entry). Reportedly, the mapping generator crashes when run on that schema, or at least when running against Oracle without filtering for a specific schema. Stack trace:

de.fuberlin.wiwiss.d2rq.D2RQException: Column @@OE.ACTION_TABLE.NESTED_TABLE_ID@@ not found in database (E86)
    at nde.fuberlin.wiwiss.d2rq.dbschema.DatabaseSchemaInspector.columnType(DatabaseSchemaInspector.java:63)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.filter(MappingGenerator.java:604)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.identifierColumns(MappingGenerator.java:592)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.writeTable(MappingGenerator.java:264)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.writeMapping(MappingGenerator.java:221)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.writeMapping(MappingGenerator.java:179)
    at de.fuberlin.wiwiss.d2rq.mapgen.MappingGenerator.mappingModel(MappingGenerator.java:165)

The issue appears to be that OE uses nested tables, and they look funny in JDBC's DatabaseMetaData. In particular, according to this, in the information schema, the columns are not in all_table_cols, but in all_nested_table_cols. Or perhaps there is a way to identify that ACTION_TABLE is not a normal table, and skip it.