NC_TABLE1 is 36 total extents. 288 eight k pages. 2.25 mb. It can be read in 5 reads – one read for each contiguous run.CI_TABLE1 is comprised of 48 extents. 3 mb. It can be read in 11 reads – again, one for each contiguous run.The SQL Server instance has the -E startup option enabled. Without that startup option, proportional fill algorithm would distribute incoming data to the 8 data files with a potential smallest allocation of a single 64k extent before rotating round-robin to the additional files in the filegroup. With the -E startup option, the smallest possible new allocation by proportional fill is sixty four 64k extents – 4 mb.That means if I can rebuild the indexes into new space at the tail of the files, the contiguity should be improved considerably.
I had never considered that the scenario described here before, so this was definitely interesting.