What are the technologies used in information retrieval?

you want information retrieval solution or Document management solutions.

Doc. management includes retrieval/archiving/ indexing documents without know much what is inside the doc. Kofax, Flienet, Docsafe are such solutions.

For information retrieval solution databases are great. and nowadays we have SQL databases, and as well as noSQL databases. it all depends on your data retrieval/update/insert frequency, data velocity, data size and other factors to decide which database to use.

The technologies used for Document retrieval are Electronic Document Management (EDM), digital image processing, large capacity storage, hypertext, multi-media documents, high bandwidth communication channels, electronic printing, electronic mail & fax. A newer technology is digital image processing which represents a page of a paper document with a digital image of that page. Stronger desktop workstations, Storage media, Networks, User friendly software, Operating systems are the technologies for Document Management