I have a large partitioned time series table where each partition is stored in it's own file. Since it's time series based partitioning divided by week and I'm only storing data that is new I have never more than 2 partitions I'm actively writing to at once. I have a FILLFACTOR set to 75 on the index since the data is coming in somewhat randomly.
The old data partitions are taking up quite a bit of space, utilizing only about 60-70% of that space. Is it possible to automatically change the FILLFACTOR on said partitions, rebuild the indexes and shrink the files? Since I'm not writing to those partitions anymore they shouldn't grow back in size.