On Wed, Jan 26, 2011 at 5:31 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
In the end I think this is mainly an issue of setting appropriate expectations in the documentation. I've added the following text to the ALTER TABLE manual page:
<para> After this command is executed, the index is <quote>owned</> by the constraint, in the same way as if the index had been built by a regular <literal>ADD PRIMARY KEY</> or <literal>ADD UNIQUE</> command. In particular, dropping the constraint will make the index disappear too. </para>
I'd change that last sentence to:
... dropping the constraint will drop the index too.