Hello,

I have a daily loading process for a delta table and has a ‘optimize table’ step at the end. The optimize operation used to take about 5 minutes, but now takes about 3.5 hours. One thing I noticed from 'describe history' is the operationMetrics captured some increase in numRemovedFiles/numRemovedBytes/numAddedFiles/numAddedBytes (highlighted in red below).

I checked the source files, which are of similar size as before. I am wondering where I should look to see what caused the increase in numRemovedFiles/numRemovedBytes/numAddedFiles/numAddedBytes?

Thank you.