Re: Dropping behavior for unique CONSTRAINTs

On 3/4/23 02:03, Peter J. Holzer wrote:
[snip]
> So your plan is to create a unique constraint (backed by a unique
> index) and then to drop the index and keep the constraint?
>
> That doesn't work. A unique constraint can't exist without a (unique)
> index. Think about it: With a unique constraint PostgreSQL needs to
> check for every insert whether the value already exists in the table.
> Without an index this would mean a full table scan.

I cut my teeth on an RDBMS which didn't automagically create a backing 
index.  You had to do it yourself...

(Autocommit and the default transaction mode not being SERIALIZABLE were 
also a shock when I started using other systems.)

-- 
Born in Arizona, moved to Babylonia.