Last tested: Aug 6, 2020
I have some LookML fields that I'm not using. They are currently hidden with `hidden: yes`. I'm concerned that it may be a performance cost to keep them. Should I delete them to save database strain?
Writing a field in LookML does not immediately query the database. The database is only queried once you select that field in an Explore. So, if a field is hidden, and thus doesn't show up in the explore, it can't be selected, and so will never impact the database.
With that said, it doesn't matter too much whether you hide or delete.
The advantage of hiding is that you have the fields there in case you ever decide to unhide them.
The advantage of deleting is that your view file has slightly fewer characters, which makes LookML validation slightly faster.