Optimising lookup tables

Hi all,

We've got a form which measures growth in children using the setup as described in the forums here. We noticed that by using Months in the lookup tables for the Z -scores we were getting small innacuracies. So we have shifted the lookups to use Days old rather than months, and the form has drastically slowed down, 20s time to open form and laggy progression through the form. I've gone back to the Monthly lookups and the s[peed issues resolves. We have 3 tables x 5 columns x 5 000 rows each). And in the form we do a lot of < and > type zscore lookups and display cards to show the scores and past growth measurements.

In terms of optimizing the performance, I have looked into:

  1. Indexing the lookups, but that won't help much as they are the <> type of calculation and not the simple = type.
  2. trying to use a Combo box for appearance but these are hidden calculations so not so this doesn't seem to be an option.
  3. I have both a pre and a post in the form. Would it be beneficial to split those out into their own forms, so have a pre and a separate post?

Is there a better way i should be looking at this? Is there a workaround for the time issue when vertically scaling lookups?
Thanks

Solved: The solution was to index the z-score lookup tables. But only the Gender column in tables.