On Thu, 2012-08-23 at 09:38 +0000, matthew.p.kusnierz@jpmorgan.com
wrote:
> Multi-column unique indexes allow duplicate rows to be inserted if any of
> the indexed columns are inserted with a null.
That is mandated in the SQL spec, and is documented here:
"For the purpose of a unique constraint, null values are not considered
equal."
-- http://www.postgresql.org/docs/9.2/static/sql-createtable.html
NULLs can be confusing, I know.
Regards,
Jeff Davis
