Hi Sanjay,

You can configure database while installing the platform server. Please check below link -

https://success.outsystems.com/Documentation/11/Setup_and_maintain_your_OutSystems_infrastructure/Setting_Up_OutSystems/Default_Platform_Server_and_database_configurations

Thanks

Vinod

Hi,

The previous reply is correct for onpremise installations, then you decide yourself. 

If you have a Google cloud license the default is MS SQL server. You can request the database to be Oracle. You have to request that as part of the license, so before the OutSystems cloud infrastructure is provisioned for you.

Regards,

Daniel