A relational database system uses a system catalog to store schema information, such as details about tables and columns. The MonetDB SQL system catalog is a collection of regular mostly readonly system tables and views located in the schemas "sys" and "tmp". The relations are modified indirectly through SQL commands. Some system views are implemented as wrappers around table producing system functions to present internal bookkeeping information.
Below you find a synopsis of the system tables and views currently provided. In addition, graphical user interfaces, such as SQuirreL, can be used to interactively browse their content.