> Make the table: > id | year | value > ---+------+------ > 1 | 1970 | 23 > 1 | 1971 | 25 > 1 | 1972 | 28 > ... > 2 | 1972 | 5 > 3 | 1971 | 94 > 3 | 1972 | 102 > primary key: (id,year) > value not null > and be ready. >the import/update reasons are pretty easily solved >that way too. then your primary key will consists of two fields. I prefer the primary keys with one field only. -Franz ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match