PDFlib TET PDF IFilter 4.0 Manual

3.6 Indexing Metadata Properties as Text
Most text retrieval engines support property queries in some way. However, querying
for properties may not be possible with retrieval products which support only full-text
search, e.g. SQL Server. In another scenario, explicitly searching for properties may not
be desired if you want to search for any occurrence of the search term, regardless of
whether it occurs in the document content or some property. In both situations you can
instruct TET PDF IFilter to include all properties in the full-text index. In order to distinguish
the property from actual document content, TET PDF IFilter can optionally prefix
the property values with a string which makes it easier to identify properties as such in
situations where the search engine does not directly support property searches. Fixed
prefixes will be used for the predefined properties listed in Appendix A, »Predefined
Metadata Properties«.
While indexing properties as text allows limited property searches in environments
which otherwise do not support property searches at all, you should be aware of the fact
that the property searches are limited. For example, Boolean or other expressions are
not available for property values.
XML configuration for indexing metadata as text. To index metadata properties as
text set the metadataHandling attribute of the Filtering element to propertyAndText (to
transparently blend the properties into the main text) or propertyAndPrefixedText (to
identify the properties with a prefix):
The optional prefix which will be prepended to custom properties when filtering the
document can be specified for custom properties in the textIndexPrefix attribute of the
Property element:
...
The prefixes which will be prepended to predefined properties are constructed according
to the following scheme:
TET__
where period characters ’.’ in the property name are replaced with underscore characters
’_’ (see Table 3.2 for examples).
Table 3.2 Prefixes for indexing metadata properties as text
Property set collection sample property name prefix for indexing metadata as text
Shell System.Author TET_System_Author_
TET PDFlib.TETPDFIFilter.pdfversion TET_pdfversion_
XMP dc:contributor TET_dc_contributor_
Image photoshop:DateCreated TET_photoshop_DateCreated_
3.6 Indexing Metadata Properties as Text 45