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Easy way to estimate a table size in the future

The CD also includes a set of stored procedures you can use to calculate estimated space requirements when the table and indexes have already been built. The main procedure is called sp_EstTableSize, and it requires only two parameters: the table name and the anticipated number of rows. The procedure calculates the storage requirements for the table and all indexes by extracting information from the sysindexes, syscolumns, and systypes tables. The result is only an estimate when you have variable-length fields. The procedure has no way of knowing whether a variable-length field will be completely filled, half full, or mostly empty in every row, so it assumes that variable-length columns will be filled to the maximum size. If you know that this won't be the case with your data, you can create a second table that more closely matches the expected data. For example, if you have a varchar(1000) field that you must set to the maximum because a few rare entries might need it but 99 percent of your rows will use only about 100 bytes, you can create a second table with a varchar(100) field and run sp_EstTableSize on that table.