While using the 'Profile' custom resource and its Send Log extension feature we see a pop up 'Adding fields may affect Performance'. We would like to know details about this so that we can decide how we can use it for our purpose.
Is there any guidance on how many fields we can add comfortably without affecting performance?
If we plan to use just for Delivery Log extension and not use in Dynamic Reporting, will it still affect the performance?
When you say it affects the performance, can you elaborate, which performance it will impact?
When it comes to performance there isn't a set formula. This notification is thrown because theoretically adding one field could significantly impact performance if done incorrectly. Performance impact will really depend on how much data in general is being added, if those fields are going to be utilized in query joins, and if so then whether those fields are indexed.
I would check out the documentation below to get a better idea of how to configure the extensions and if you really want to go in depth then I'd recommend doing a web search on adding fields and database performance. There are any number of sites that go in depth into database management and performance.