All Search Engine Database

A search engine database is an information retrieval system built to index large bodies of text or other content and return the most relevant matches for a user query, rather than to serve as a system of record for transactional data. It typically builds an inverted index mapping terms to the documents that contain them, so a query can be matched against millions of records without scanning each one directly, and it ranks the matches by relevance signals such as term frequency, field weighting or recency. Beyond the search engines that cover the public internet at large, this class of system underlies site specific and enterprise search, log analysis and the full text lookup layer many applications place in front of a separate primary data store to handle free text queries that store was never designed to answer efficiently on its own.