How I debugged a Delta Lake DESCRIBE HISTORY timeout (and what's actually causing it)

If you have ever run DESCRIBE HISTORY on a Delta table that receives streaming data every 60 seconds and watched it either hang for hours or crash with an OutOfMemoryError , you are not alone and you are not doing anything wrong. The problem is architectural, and once you understand the internals, the fix becomes a lot clearer. Here is what I learned after digging into why this happens and what you can actually do about it. How the Delta transaction log works Every write to a Delta table, INSERT