Subject Unique constraint not an index? was Re: Error:Object is in use
Author dianeb77@hotmail.com
--- In ib-support@y..., "Ivan Prenosil" <prenosil@m...> wrote:
<...>
> Although it is hard to imagine database system without indexes,
> the fact is that SQL92 does not know them.
> Standard SQL language describes what results you are interested in
> (like that you want values in column to be unique=unique
constraint),
> but does not care about implemetation details (like that you want
> to create index to speed up query or to enforce uniqueness).
>
> Indexes are vendor specific extensions (I am not sure about SQL99),
> they are just auxiliary structures intended to speed up some
operations.

Correct, and still true in SQL99.

db
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