Disables compression indexes. If compression is disabled, no form of compression is used for hashed indexes, and prefix compression or suffix compression is used for sorted indexes. Prefix compression is the compression of the first bytes of an index key that are common in consecutive index keys. Prefix compression saves space by not storing these common bytes of information. Conversely, suffix compression is the compression of the last bytes from adjacent index keys. These bytes are not necessary to guarantee uniqueness. You cannot enable index compression using the ALTER INDEX statement once you specified the DISABLE COMPRESSION clause of the CREATE INDEX statement. Index compression is disabled by default.