The %NOT Optimization
It is often necessary to exclude a single member of a level. To do this easily, you can use the %NOT function, which is an InterSystems extension:
SELECT aged.[age bucket].MEMBERS ON 1 FROM patients WHERE aged.[age group].[0 to 29].%NOT
1 0 to 9 *
2 10 to 19 *
3 20 to 29 *
4 30 to 39 166
5 40 to 49 139
6 50 to 59 106
7 60 to 69 86
8 70 to 79 62
9 80+ 41
Queries that use the %NOT function run more quickly than equivalent queries that use EXCEPT.
