[Rt-devel] create index on groups(instance) is a booster

[Palle Girgensohn]

I've found that an index on groups (instance) is a real booster. It will 
help this very common query:

 SELECT  * FROM Groups WHERE lower(Domain) = 'rt::ticket-role' AND Instance 
= '1888' AND lower(Type) ='requestor';

at least on postgresql with my database, the query will move from 20 ms to 
1 ms.

/Palle