[syslog-ng] Recommended db for syslog?

Hi, I'd like to store my logs in a database, instead of text files. Many years ago I thought a mysql or postgresql can be excellent for that purpose, but today... I'm a little bit confused. Should I use an RDBMS? Or should I turn to noSQL databases? (mongoDB?) The only thing I'm sure, I don't want to use any other log manager(??) software (like Graylog, elasticsearch etc.) I'd like to use only a syslog-ng server with a database. Could you help me? Victor :)