Tweaks to compression macro

pedromachado [36 minutes ago]
Hi @drew.banin I tested the macro and noticed a couple of things: 1) It's unable to create a new backup table if one already exists, a problem for subsequent invocations if drop_backup=False is used and 2) It seems to create a new table even if the ideal encodings have not changed. I took at quick look at the logs and this seems to be the case. Could you confirm?

You were trying to figure out how to prevent it running on every incremental run. I think we can live with the extra `analyze compression` but it would be great to skip the creation of the new table if encodings are optimal.

Also, I haven't studied the code in detail but I don't think the macro keeps the original dist, sort settings if none are specified as macro parameters. It would be great to support this.