Re: help with dual indexing

Orion Henry <orion(at)trustcommerce(dot)com> writes:
> The queries usually are in the form of, where "user_id = something and
> event_time between something and something".

> Half of my queries index off of the user_id and half index off the
> event_time. I was thinking this would be a perfect opportunity to use a
> dual index of (user_id,event_time) but I'm confused as to weather this
> will help

Probably. Put the user_id as the first column of the index --- if you
think about the sort ordering of a multicolumn index, you will see why.
With user_id first, a constraint as above describes a contiguous
subrange of the index; with event_time first it does not.

regards, tom lane