Hi David,

Don't know if this is possible or not but couldn't you write your
COMPLETE records to a .HIST file, keeping the rest of the data in a
.CURR file.  Then have a PART file definition that binds the two parts
into what is the current filename?  You could then index and select off
the .CURR file and be able to process off either the PART filename or
the .CURR filename.

I'm not real familiar with PART files but it seems like it should work.
I'm not even sure if PART files are available in UD but thought the
suggestion was worth mentioning.

Good luck,

Bob Woodward
Senior Programmer/Analyst
Harbor Wholesale Grocery

 
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of David Wolverton
Sent: Wednesday, August 02, 2006 6:53 AM
To: u2-users@listserver.u2ug.org
Subject: RE: [U2] [UD] Indexing 'Best Practices' 

OK - sold!  Virtual field to move COMPLETE to NULL is the answer... As I
was
driving back to the hotel after doing that post last night, I got to
thinking that the Virtual Field computation would strictly be
CPU/Memory,
which means I can do A LOT of that for the cost of a single disk access.
And with the B+Tree design, we are doomed to at least TWO disk reads in
every case (unless you happen to hit the Root record!) - the first to
the
'lead' block, and then a read either 'left' or 'right' - and fresh from
sleep, I can see that as the index grew, that could turn into 3, 4, or
50
traversals (aka Disk reads) left or right to position the key on write.
The
leaf size is 4K - PERIOD. So every 100 or so records in a leaf, there
would
be some sort of shift of level push that would involve even more write
traffic.

More than likely I'll create a new dictionary that is a Virtual Field,
and
index that NO.NULLS and change the routines that need expedited selects
that
we were using the index for anyway - any report that would allow
"COMPLETE"
as an option will probably have to go through the whole file, so we may
have
to create 'versions' of the report - a faster "Select Only From
non-COMPLETE" Version that can use Indexes, and a slow, but inclusive
"Can
Include COMPLETE" version which will use the unindexed attribute.

Thanks for all who responded on and off list!  If anyone else knows
magic
that goes on behind the scenes on indexes, or has recommendations,
please
continue to chime in!
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