Difference between encode and compress stage

[agpt]

Hi All,

Can any body please tell me what is the difference between encode and compress stage? Similarly between decode and expand stage?

[chulett]

Welcome aboard! And... not being facitious but one is meant to be used with compression and the other encryption, two completely different things. And as you noted, the last two you listed 'undo' what the first two (or other processes) have done.

Note that all PX stages are explained in the Parallel Job Developer Guide, these ones are in Chapter 6: Processing Data. If you're wondering why they both mention "gzip" I believe that's a mistake in the documentation of the Encode stage. From the gzip site:

Does gzip support encryption?

No. Simple encryption algorithms such as that of PKZIP can be broken. And adding strong encryption such as that of PGP to gzip would not make much sense because that would duplicate the functionality of those encryption programs. PGP already incorporates the gzip compression code, so use PGP if you need compression plus strong encryption.

If you are satisfied with weak encryption, you can use zip.

Some compressions programs can do encryption as well but gzip isn't one of them. So perhaps mentioning PGP for the Encode stage would have made more sense. At least to me.

[agpt]

Thanks a lot Chulett........... It makes more sense now to me. You are right I got confused with the description given in Parallel Job Developer Guide.