What Can Be Indexed
Six extractors between them cover the document formats the platform can read.
Where to find it
Architect Panel → Data:
- Documents — the library being indexed
The extractors
- PDF.
- Word and OpenDocument — .docx, .doc, .odt, .rtf.
- Spreadsheets — .xlsx, .xls, .ods, .csv.
- Presentations — .pptx, .ppt, .odp.
- Plain text, HTML and e-mail — .txt, .html, .htm, .eml, .md, .json, .xml.
- Scanned images, through optical character recognition.
Availability is checked, not assumed
Each extractor depends on a library, and the platform checks whether it is present. Where one is missing, extraction for those formats is refused with a stated reason rather than silently producing nothing.
Only plain text is always available, because it needs no library.
Scanned documents are a separate problem
A scanned page is an image. Ordinary extraction reads nothing from it, so it needs optical character recognition, which needs a configured provider.
If your library is largely scans, that is the capability that matters, and it is worth confirming before assuming documents are searchable.
A PDF is not necessarily text
The common misunderstanding. A PDF produced from a word processor contains text; one produced from a scanner contains an image of text. They look identical to a person and completely different to an extractor.
The character count is how you tell them apart.
Recognition is not perfect
Optical recognition produces approximately the right text. Good enough to find a document; not good enough to rely on for a figure or a reference number without checking the original.
Check what your library actually contains
Before deciding anything. A sample of fifty documents, their formats and their character counts, tells you whether your archive is searchable and what would make it so.
Ask for text where you can
A supplier sending a text-based PDF instead of a scan is a change worth requesting once, and it removes the recognition problem entirely for everything that follows.
Say what is searchable
Users assume everything is. Somebody who cannot find a document concludes the search is broken rather than that the document is an image, and they stop trusting the search.
Worked example
A sample of a document library found a third were scanned PDFs with near-zero character counts. Recognition was configured for those, and the supplier producing most of them was asked to send text-based files instead — which removed the problem for everything received afterwards.
Recommendations
- Sample your library before assuming it is searchable.
- Character count distinguishes a text PDF from a scan.
- Ask suppliers for text rather than scans.
- Tell users what is and is not searchable.