The locate program  of findutils scans one or more databases of filenames and displays any matches. This can be used as a very fast find command if the file was present during the last file name database update.There are many kinds of databases nowadays, relational databases (with query language e.g. SQL), NoSQL databasesdocument-oriented databases (e.g. MongoDB)Key-value database (e.g. Redis)Column-oriented databases (e.g. Cassandra)Graph databaseSo what kind of database does updatedb update and locate use?  Thanks.
What kind of database do `updatedb` and `locate` use?
find;database;locate;updatedb
Implementations of locate/updatedb typically use specific databases tailored to their requirements, rather than a generic database engine. Youll find those specific databases documented by each implementation; for example:GNU findutils is documented in locatedb(5), and is pretty much just a list of files (with a specific compression algorithm);mlocates is documented in mlocate.db(5), and can also be considered a list of directories and files (with metadata).