Re: Best way to get all different values in a column

On Fri, Oct 14, 2005 at 06:02:56PM +0200, ext-christian.roche@nokia.com wrote:
> Does anyone here know what  is  the most efficient way to  list all
> different values of a given column with low cardinality ?  For instance
> I have a table with columns DAY, NAME, ID, etc.  The table is updated
> about each week with thousands of records with the same (current) date.
> Now I would like to list all values for DAY, only if possible without
> scanning all the table each time I submit the request.
> I can think of:
> ...
> Solution 6: Store the values in a separate table, recreated each time
> TABLE is updated.

I've found a variant on 6 to work well for this problem domain.

Why not insert into the separate table, when you insert into the table?
Either as a trigger, or in your application.

Cheers,
mark

--
mark@mielke.cc / markm@ncf.ca / markm@nortel.com     __________________________
.  .  _  ._  . .   .__    .  . ._. .__ .   . . .__  | Neighbourhood Coder
|\/| |_| |_| |/    |_     |\/|  |  |_  |   |/  |_   |
|  | | | | \ | \   |__ .  |  | .|. |__ |__ | \ |__  | Ottawa, Ontario, Canada

  One ring to rule them all, one ring to find them, one ring to bring them all
                       and in the darkness bind them...

                           http://mark.mielke.cc/