You could bypass the business layer and directly to the data layer to get the records you want. That will give you a performance edge. But it will also defeat one of the major benefits of 3-tiers design: module independancy. What if there is a new business rule that forbids certain records? What if you change the data layer (from VFP to SQL server for example)? You will not only have to modify the business and/or the data layer, but the interface layer also.

I would recommend bypassing the business layer only in rare occasion, where the speed is very important. But be sure to document this behavior.

>I am on the start of the long way of 3 tier programming.
>I am currently rewrite one of my prev. app.
>If I understand the 3 tier prog. model. presentation tier can only communicate directly with business object and so, mustnot acces to database tier.
>But what if the presentation tier want to get a list of some records. (e.g. a form with a list of invoices). Should it ask the business object to pull the list into a cursor and give back the alias of the cursor? Im am afraid, that it slows down the app. And how to use a grid with its built-in sql capacity? Or is there a better algorythm?