Our Client suggesting to have the local data storages for each and every drop down. so that if we have 1000 drop downs (values are configurable) , we will be getting 1000 local data storage and Data pages. Is this a good approach rather than having a one Data page?
Assuming I am reading this right then the answer is yes, this is correct and would be the best practice.
To clarify: If you have 1000 different lists then you will have 1000 instances of local storage tables and at least 1000 Data Pages, but if you have 5 dropdowns and all need to display the same list then you only need 1 instance table in local storage and 1 Data Page.
One assumption is that the list you need does not already have a system of record, for instance if you have a third party product catalog system and you need a list of product categories or just a list of products then you don't want to also have to maintain that list in Pega local storage as well, so you should use some integration to pull the list directly from the product catalog and make it available to the dropdown via a Data Page.