ADF and DBA have 2/3 letters in common

I was doing DBA work this week. We installed our application in different schema and the performance dropped to hell.

The View objects queries that we spend a lot of time tuning in previous schema now they had different execution plan.

So I check the instance properties and I see OPTIMIZER_MODE=ALL_ROWS.
This option means that when you do a query the optimizer thinks that you are trying to retrieve all data from the query so it check the statistics to find the best plan to retrieve all rows usually by full table scans. The all_rows mode is generally used during batch-oriented processing and for data warehouses where the goal is to minimize server resource consumption.

This is not the case in our application and I guess in most ADF applications. I changed it to OPTIMIZER_MODE=FIRST_ROWS. The first_rows optimizer_mode is generally used in online system where the end-user wants to see the first page of query results as quickly as possible. This had a huge positive effect in the performance of our fusion application.
May be this is considered basic for DBAs but it seems that ADF developers should know also in order not to loose time tuning view objects in a wrong configured database.