Can I drop primary key index without dropping primary key constraint in postgresql?
+2
A:
Your question is a bit confusing. I think you must mean this:
Can I drop an index on a column but still keep the uniqueness constraint on that column?
No. A uniqueness constraint requires an index. You can make your constraint into an ordinary non-primary index, but you can't make it not an index.
Also, read about primary keys in the documentation:
Technically, a primary key constraint is simply a combination of a unique constraint and a not-null constraint.
So if a column is a primary key it has by definition a unique constraint and therefore also an index. You cannot have a primary key that isn't an index.
Mark Byers
2010-04-22 23:27:47