(2) For physical documents I use a Fujitsu ScanSnap iX500[4] for scanning. A runtime-licencse of ABBYY FineReader for OCR is included. The resulting PDF has embedded text which I extract using pdftotext[5]. I wrote a python application to search and tag this documents. It loads all the text in-memory which is perfecty fine as I have < 10,000 documents. I use it since 5 years and it works OK.
[1] https://github.com/gwgundersen/anno
[2] https://news.ycombinator.com/item?id=22033792
[4] https://www.fujitsu.com/global/products/computing/peripheral...