RE: Memory Allocation Question

["Jonathan Mason" <jonathan.mason@xxxxxxxxxxxxxxxx>]

Hi Tony

<snip>
  My question is, what is the limit, and is there one.
</snip>

There is a limit of 16MB for user spaces.  The odd time's I've hit the
limit, the program crashed.

I've got a couple of thoughts and some questions I'd like to share and ask
if I may.

First, I'm thinking that you're trying to identify duplicate entries for
patients?  If so, then would the SS# be the most likely field to match on,
on the basis that it should be unique for all individuals?

I think the way I would approach this would be to have two, possibly three,
logicals over the database.  The logicals would be in:

        Logical 1:      SS#, DOB, Name
        Logical 2:      SS#, Name, DOB
        Logical 3:      DOB, Name, SS#

If you process each of the logicals in key order, checking the first two key
fields for a level break then you're processing a maximum of 10,500,000
records instead of the 13 trillion you're reading at the moment.  You only
need the three logicals as you're looking for two fields matching to
generate a hit - SS#, DOB, Name and DOB, SS#, Name would give exactly the
same results but in a different sequence.

Hope that helps a little

All the best

Jonathan
www.astradyne-uk.com