SELECT C.TABSCHEMA, C.TABNAME, C.COLNAME
FROM SYSCAT.TABLES AS T, SYSCAT.COLUMNS AS C
WHERE T.TBSPACEID = -- TBSPACEID
  AND T.TABLEID = -- TABLEID
  AND C.COLNO = -- COLNO
  AND C.TABSCHEMA = T.TABSCHEMA
  AND C.TABNAME = T.TABNAME