Tom.Thomson (7/26/2011)
Good article.On the compressed backup of a compressed table question: no, the compression algorithms/formats are different, so backing up a compressed table/index involves decompressing and then recompressing; so the CPU impact is higher than you might expect.
Do you know for certain that a backup uncompresses and then recompresses compressed tables? I thought it just backed up the data pages as they were on the disk, and applied compression to them. (So there shouldn't be any uncompression CPU overhead during a backup.)