Hi Saif,

Data Action - If we need to fetch data from Server Action, Rest/Soap API, SQL Query then we can use Data Action.

Fetch Data from Database - Aggregates are used to fetch data from database entity.

Please see the below links -

https://success.outsystems.com/Documentation/11/Developing_an_Application/Implement_Application_Logic/Actions_in_Reactive_Web_and_Mobile_Apps?_gl=1*pasly2*_ga*MzE5MTA5ODAzLjE2NTA5NDA5ODM.*_ga_ZD4DTMHWR2*MTY1MjY3NDIzMy40LjEuMTY1MjcwMzkyNC4xNw..#data-actions

https://success.outsystems.com/Documentation/11/Developing_an_Application/Use_Data/Query_Data/Fetch_and_display_data_from_the_database_in_OutSystems

https://success.outsystems.com/Documentation/11/Developing_an_Application/Use_Data/Query_Data/Fetch_and_display_data_from_an_integration

Thanks

Vinod

There is also a good article in case you want to use to do pagination, sorting and filtering using data actions that I think is quite useful.

https://itnext.io/paginating-sorting-and-filtering-data-from-a-data-action-f5cb997fdc60

Reagrds,

Márcio

Hi Saif,

Adding one point 

Never create an action to execute an Aggregate. When the query is isolated in an action by itself, the Platform can't optimize the number of fields to be retrieved.

For more detail Kindly visit  below link.

https://success.outsystems.com/Documentation/Best_Practices/Performance_and_Monitoring/Performance_Best_Practices_-_Queries

Best Regards

Devendra