TDA displaying an error "Snap shot is too old - Toad cannot retrieve records or run query". (4258567)

TDA displaying an error "Snap shot is too old - Toad cannot retrieve records or run query".

TDA displaying an error "Snap shot is too old - Toad cannot retrieve records or run query". This happent when attempting to run long running queries, then wait for about 3-4 hours.  Sometimes the query won't run and I will get the error "Snapshot is too old".  Or  After the query runs, it brings ONLY 500 records (i.e. the default). If I did not extract all the data at that time and waited for few hours and tried to extract the data later (Such as the next morning), I get the same error. I need to know how TDA/oracle performs behind the scenes once a query is executed. Does oracle take a snap shot of the affected tables when the query starts executing or does this happen at the end of the execution time. If I know that, I can construct my queries accordingly. Let me demonstrate this in an example: If I ran a query with a condition on Unit_Status = "Open". I run my query at 8:00AM. My query takes 2 hours to run. I had 2,000 units that are open at 8:00 AM (When I started my query). However, at 9:00AM, there were 9 units that got closed (i.e... Re: Regarding |SR Number:2018117| - TDA 3.0, sent to report shut down toad