Re: [SQL] searching time arrays

Nathan Gelbard <gelbardn@intus.net> writes:
> given the table below, how would i determine which name is
> avail on a givin day at a givin time? the time arrays
> contain an a list of hours a support person is available;
> '{09:00:00,10:00:00,11:00:00,12:00:00}' etc.
> any thoughts?

> CREATE TABLE support_sched
> (
>         name varchar(30),
>         monday time[],
>         tuesday time[],
>         wednesday time[],
>         thursday time[],
>         friday time[],
>         saturday time[],
>         sunday time[]
> );

I wouldn't design the table that way --- you've made it really hard
to answer that sort of query, rather than exploiting SQL's strengths.
Instead, consider a table that has one record per availability-window,
say
name text,dayofweek int2,        -- 1-7 = Sun-Sat, or some such encodingstarttime time,stoptime time

and you just make as many of these as there are contiguous time-
windows in each support person's schedule.  There might be twenty
or so records per support person, but so what.  Now your query
looks like
SELECT name FROM support_schedWHERE dayofweek = appropriatevalue AND    now >= starttime AND now <= stoptime;

(you could also reduce the last two clauses to a BETWEEN if you
happen to like syntactic sugar).

If you're concerned about storing twenty or so copies of a person's
name, make that column be an integer ID code instead that you can look
up in a separate table of support people.  I dunno if I'd bother with
that if the data is *only* a person's name, but as soon as you start
adding phone number, home address, mother's maiden name, yadda yadda
you will want the separate table...
        regards, tom lane