checksum
Usage:
omode=checksum
Calculates a checksum from all the data in the table. The checksum is written to standard output in hexadecimal; row and column counts are also written.
If two tables have the same checksum it is extremely likely that they contain the same cell data. If they have a different checksum, their cell data differs. By default, the checksum implementation uses Adler32, which is fast but not cryptographically secure.