Great post, is it fair to say then that if you are wishing to bulk extract data from a table then you are at the mercy of the original cache design and only way to improve performance would be to change the database design?

Been grappling with cache performance for a couple of years with some of our clients.

https://community.intersystems.com/post/data-extraction-using-sql-odbc

Thanks Benjamin, we were advised previously to look at tune table via a WRC we had open. We ran a number of TT processes one of which made performance worse so there was some reluctance from our local admin team to pursue any further. Will start to look into it again.