InfoPath Dev

I have used 3 successive cascading drop downs on the Infopath form itself so that when picking a value from the first drop down, Infopath then filters the values in the second drop down to so that only those associated with the value in the first drop down are returned. Each drop down is connected to a different field in the query in the Database. However this causes the form to slow down and crash.

The cascade works as expected but every text field and drop down field in the form then becomes slow-responding and sometimes causes Infopath to crash. Is this because I have stored the Access Database on the LAN? The Infopath form is also stored on the LAN, though eventually it will need to be run from a Sharepoint Form Library. Unfortunately the company I work for has disabled the use of Access Web Services.. I considered that option. 

Does anyone know if there is any reason why the cascade flows are causing my entire form to become slow responding? Thanks.

 Hi - do you have the checkbox for only displaying unique values selected for the drop downs? Here's a blog post I did on that - I had a form that the performance was terrible in with this option selected.

Hi Hilary

Thanks for you reply. I had tried the checkbox for only returning unique values, but that did not fix the problem as the form first had to look at all the Access table's records and then remove duplicates. A colleague of mine managed to figure out what the problem was and a solution for it.

The Access Table had circa 7000 records, and when playing around with the table, we noticed that the form became slow responding once the number of records exceeded ~2000. The main problem lied with the first drop down in the cascade, as once the second and third drop downs were used there were only a few records to filter through.

So we made a separate Access Query which only returned the column of records which was being used for the first drop down. The query itself was used to only return unique values; this took the number of records in the column to just under 2000. The original table was then used for the filterung on the second and third drop downs.

The form is now fast!