caching data in a website

In addition, you might try below,

1) Create a Class for example, DDLCache which will hold the initial value for the DDL, retrieved from the Db.
2) Store the object(which contains all the values retrieved from Db ) of type DDLCache into the Session.
3) So then you just need to check if the object of DDLCache stored into Session is null or empty, otherwise read from the Db.

More details about Session[^].

Hope it helps :)

Try
Improved Fast Access to Small Lists On ASPX Pages[^]

Simple when you are binding the dropdown then store your datga source to cache and before binding check the cache is null or empty
if null or empty then fetch from db else
read from cache.