Andrew Lazarus <[EMAIL PROTECTED]> writes:
> Because I know the 25 closest are going to be fairly close in each
> coordinate, I did try a multicolumn index on the last 6 columns and
> used a +/- 0.1 or 0.2 tolerance on each. (The 25 best are very probably inside
> that hypercube on the distribution of data in question.)

> This hypercube tended to have 10-20K records, and took at least 4
> seconds to retrieve. I was a little surprised by how long that took.
> So I'm wondering if my data representation is off the wall.

A multicolumn btree index isn't going to be helpful at all.  Jeff's idea
of using six single-column indexes with the above query might work,
though.

                        regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 7: You can help support the PostgreSQL project by donating at

                http://www.postgresql.org/about/donate

Reply via email to