Yes, this information is incorrect. MySQL does not "run in memory" moreso than other RDBMS's; it has various in-memory caches but persists your data to disk. SQL is not a database, but the language you use to talk to one. NoSQL is not a specific file-backed database but a category of software, some of which persist data to disk and some of which don't.
Comments
Yes, this information is incorrect. MySQL does not "run in memory" moreso than other RDBMS's; it has various in-memory caches but persists your data to disk. SQL is not a database, but the language you use to talk to one. NoSQL is not a specific file-backed database but a category of software, some of which persist data to disk and some of which don't.