In your datagrid, set wait for search to Yes. This way, will not try to prefill the datagrid with 120,000 objects. Then, when you navigate to the datagrid, you will need to specify some search criteria and click search to see some of your records. 120,000 is a lot of records to display on a single web page, so you are probably running into a combination of database performance constraints and web page performance constraints.
In the microflow, as Jelle said, you will need to limit your retrieve in some way so you are not running into a memory or performance issue.