This executable has to be placed in the same folder as mentioned above. With USER_FILTER an alternative executable can be referenced. The problem with this had to do with sharing the content of the PDF…. However, this would involve uploading at least one example of a PDF demonstrating this behaviour. Of course, more or less at this point, I did think about raising an Oracle Support ticket. This is where USER_FILTER came to the rescue.

However, as described above, using AUTO_FILTER just wasn’t appropiate enough in the customer’s case. Roger Ford, Oracle Product Manager, has written quite some blog posts on OIT and how that helps on Text-indexing binary documents, see here. As such, it is part of the Oracle Outside In Technology (OIT). This executable ( backed-up by a long list of libraries) is very much capable of determining the type of binary document and handling that type appropiately (well mostly). For Oracle Text, this particular filter is the ctxhx executable living in the $ORACLE_HOME/ctx/bin folder. A soon as the RDBMS needs access to the enclosed text stored in the binary document a so-called third-party filter is triggered to convert this document. For the specific text-based (ML) algorithm that had to read the converted text, it was.Ĭonversion of PDF documents using AUTO_FILTER works like this. If AUTO_FILTER would be used to text-index the document, that would not be a problem. For example, some paragraphs were converted such that each word appeared in a separate line surrounded by three additional empty lines. I did not receive error messages, but closer inspection of the resulting documents revealed textual properties the end-user would not have accepted. It worked like a charm…regrettably with the exception of just a few specific PDF documents. My first approach was to create this policy specifying the previously mentioned AUTO_FILTER.

This procedure requires a so called named policy which has to be created in advance (on-time) using CTX_DLL.create_policy. I had started to implement this business requirement using Oracle Text, specifically using its CTX_DOC.policy_filter procedure.

Oracle blob to text