This is done because of BigTree's ability to use explicit and implied parsers on columns in your views as well as View Filters. When run on demand in large data sets it would be an extremely intensive task to draw your view each time. For this reason, BigTree employes view caches.
Whenever your view is updated, your view cache is cleared. This can also be done manually through BigTreeAutoModule::clearCache("table") — where "table" is the table in which you've changed data. If you're manipulating data through the front end of your site or through custom admin components, it's a good idea to clear the view cache when you're done. You can also manually uncache or recache entries in your table and cache new entries. If you're already using BigTreeAutoModule's createItem, deleteItem, and updateItem methods, you do not need to manage the cache.