Is there a commercial RDBMS that allows one to create indices on
views?

I'm asking this partly because of BCNF.

A typical BCNF problem is (where -> is a FD)

A, B->C
C -> B

which becomes the following relations

R_A [_A_, _C_]
R_B [_C_, B]

where _X_ denotes an attribute in the primary key

since
R [_A_,_C_,B] is not in 2NF

But there's an additional constraint where the equijoin of R_A and R_B
on C would have the candidate key A,B.

Is there a way to express this last constraint (i.e., a candidate key
on a view) in an implementation system?

Cecil Chua

On Jan 14, 1:49*am, aehc... (AT) ntu (DOT) edu.sg wrote:
I'm not quite sure what you are asking, but

since a view is really just a query, then indexing it does not make
sense. The DBMS should be able to derive a query executation plan
based on the underlying tables used in the query.

If you want a theoretical answer, then post over in
comp.databases.theory

HTH
ed

On Jan 14, 1:49*am, aehc... (AT) ntu (DOT) edu.sg wrote:
I'm not quite sure what you are asking, but

since a view is really just a query, then indexing it does not make
sense. The DBMS should be able to derive a query executation plan
based on the underlying tables used in the query.

If you want a theoretical answer, then post over in
comp.databases.theory

HTH
ed

On Jan 14, 1:49*am, aehc... (AT) ntu (DOT) edu.sg wrote:
I'm not quite sure what you are asking, but

since a view is really just a query, then indexing it does not make
sense. The DBMS should be able to derive a query executation plan
based on the underlying tables used in the query.

If you want a theoretical answer, then post over in
comp.databases.theory

HTH
ed