Part XVIII — The Small-Files Tax: Compaction Strategies That Don’t Stall

Your lakehouse doesn’t slow down because the data grew. It slows down because the file count did — and every one of those files is a tax your query planner pays before it reads a single byte. Part I | Part II | Part III | Part IV | Part V | Part VI | Part VII | Part VIII | Part IX | Part X | Part XI | Part XII | Part XIII | Part XIV | Part XV | Part XVI | Part XVII | Part XVIII The 58-Minute Query That Read Nothing Useful The Slack message landed at 9:41 PM, eleven minutes into the nightly reporting window: “finance dashboard is stuck again.” Not failed — stuck. The aggregate query over our ev