The documentation at https://www.monetdb.org/Documentation/Manuals/SQLreference/UUItype indicates that a UUID type is supported in MonetDB and gives the example select uuid(); +--------------------------------------+ | uuid | +======================================+ | 65950c76-a2f6-4543-660a-b849cf5f2453 | +--------------------------------------+ which appears to output from mclient. When I try the same with mclient I receive auto commit mode: on sql>select uuid(); SELECT: no such operator 'uuid' mapi.h only shows support for the following types #define MAPI_AUTO 0 /* automatic type detection */#define MAPI_TINY 1#define MAPI_UTINY 2#define MAPI_SHORT 3#define MAPI_USHORT 4#define MAPI_INT 5#define MAPI_UINT 6#define MAPI_LONG 7#define MAPI_ULONG 8#define MAPI_LONGLONG 9#define MAPI_ULONGLONG 10#define MAPI_CHAR 11#define MAPI_VARCHAR 12#define MAPI_FLOAT 13#define MAPI_DOUBLE 14#define MAPI_DATE 15#define MAPI_TIME 16#define MAPI_DATETIME 17#define MAPI_NUMERIC 18 Is it possible to get MonetDB to generate UUIDs and how is the type supported in mapi. Thanks Doug Service