I have a bunch of partitioned tables that are "row" compressed. I need to unload those table to migrate the data for some testing, and I want to estimate how much raw data there is in the tables (uncompressed). There are conflicting notes in the man pages for SP_ESTIMATE_DATA_COMPRESSION_SAVINGS. in one place it says "If the table, index, or partition is already compressed, you can use this procedure to estimate the size of the table, index, or partition if it is recompressed." In another place it says "If a table is enabled for compression, use sp_estimate_data_compression_savings to estimate the average size of the row if the table is uncompressed." If I run the SP against one of the tables, I get
So, other than doing a sample unload of the tables to a flat file then extrapolating it myself, is there a way in the engine of estimating what the uncompressed size of the data in a compressed table is?