Xapian VS Ambar

Recoll is free/open source (GPL) that can index PDFs and search them very quickly. It uses Xapian under the hood. I have over 165,000 documents indexed on an old laptop running Linux and can query them all in a split second. Source: 7 months ago

+ xapian which has been around a while, and while gpl licensed, is quite capable https://xapian.org/. - Source: Hacker News / over 1 year ago

Tangentially related if you need search without the clustering and high availability story of elastic search and friends I highly recommend Xapian. Its like the SQLite of search. Single library that provides the basic set of features you would expect in a quality search experience: facets, ranked search, boolean operators, stemming etc etc. https://xapian.org/. - Source: Hacker News / over 1 year ago

For fast searching, it usually requires indexing the files in question. There are a number of text-file indexing solutions, many of which use xapian, sphinx, or lucene/solr under the hood. Based on conditions (watching files/directories, cron jobs, new-mail triggers, etc), they'll add/remove files to the index, and you can then use a corresponding command to compose queries across that data. If it's indexed, it... Source: about 2 years ago

There is also xapian/recoll https://xapian.org/ which works great for "desktop" search. - Source: Hacker News / over 2 years ago

I don't need any other features (other than batch uploading). The best ones I've found so far are Ambar, I, librarian, and Lodestone with their multiple 'snippet' search functionality, however for various reasons they won't work with my use case.[1]. Source: almost 3 years ago

Ambar - Document Search Engine · An open-source document search engine with automated crawling, OCR, tagging and instant full-text search. Source: about 3 years ago