I have a table that is partitioned by date range - weekly partitions. The new partition starts every Monday. Data is loaded into the table during the day. Then a report is run nightly; that takes about an hour.

But recently, the report has started to take 4 hrs each Monday ! It runs in just 1 hour on the other weekdays. IT IS NOT A SCHEDULING ISSUE. The only thing I could think of was a fresh partition was being queried - has anyone else run into something like it ? Does it makes sense ?