Re: Proper database design for best performance?

Use char(1) containing NULL for processed rows and anything for non-processed rows. If all is well, NULL still won't be go into the index, so the index will be very small.

Hth,

Sybrand Bakker, Oracle DBA

<jbrychka_at_my-deja.com> wrote in message news:89mg61$132$1_at_nnrp1.deja.com...
> I would like some ideas on the best way to set up data for fast access.
>
> I have a very large table that I look up for records that have not been
> processed. The query would look something like this:
>
> select column_a
> from table
> where date_column is NULL
>
> This type of query cannot use an index so it is very slow. To get
> around the index issue I was thinking of defaulting this date_column to
> a specific date that I would then put in my query. Something like this:
>
> select column_a
> from table
> where date_column = :default_date
>
> This way I could use an index. The only thing I don't like about this
> is that I am putting this bogus date value in the column.
>
> Another option is to add an indicator column that would default to "N"
> for new records and then get updated to "Y" when processed. The issue
> I have with this is that I still need the date column to know when it
> is processed so now I have two columns instead of just one which causes
> the table to use more table space.
>
> If anybody has any opinion on this or other alternatives, I would like
> to hear about it.
>
> Thanks,
>
> Jim
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Thu Mar 02 2000 - 00:00:00 CST