On Mon, Oct 31, 2011 at 2:08 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>> Multicolumn indices on (c1, c2, ..., cn) can only be used on where
>> clauses involving c1..ck with k<n.
>
> I don't think that's true. I believe it can be used for a query that
> only touches, say, c2. It's just extremely inefficient.
Does postgres generate those kinds of plans?
I do not think so. I've never seen it happening.