DBpedia difference between dbo and dbp predicates/properties

From DBpedia-disccusion mailing list: https://groups.google.com/forum/#!topic/thosch/CN1kBh3auCk

DBpedia differentiates between information extracted from the wikipedia dumps without an alignment to the DBpedia ontology (raw extraction) and the mapping based extraction (based on mappings between wikipedia infoboxes and the ontology).

• http://dbpedia.org/property/ (prefix dbp) for representing properties extracted from the raw infobox extraction
• http://dbpedia.org/ontology/ (prefix dbo) for representing the DBpedia ontology  

Mapping-based Properties

High-quality data extracted from Infoboxes using the mapping-based extraction. The predicates in this dataset are in the /ontology/ namespace.

Note that this data is of much higher quality than the Raw Infobox Properties in the /property/ namespace. For example, there are three different raw Wikipedia infobox properties for the birth date of a person. In the /ontology/ namespace, they are all mapped onto one relation http://dbpedia.org/ontology/birthDate. It is a strong point of DBpedia to unify these relations.

Filtering dbo properties using SPARQL:

SELECT ?s ?o WHERE
{
  ?s <http://www.w3.org/2000/01/rdf-schema#label> ?o .
  FILTER regex(str(?s), "^http://dbpedia.org/ontology") .
}

In case you need to exclude some properties such as http://dbpedia.org/ontology/wikiPageRedirects,

FILTER ( STR(?property) NTO IN ("http://dbpedia.org/ontology/wikiPageRedirects") )