Ron Johnson <ronljohnsonjr(at)gmail(dot)com> writes:
> Cascading statements really need a DRY RUN option.
[ shrug ] BEGIN/ROLLBACK serves that purpose fine, in fact better
than a per-statement "dry run" option would do: you can run several
dependent DDL statements and then look around at the results before
committing (or not).
Your claim that rollback is slow seems to be born of experience with
some other DBMS.
regards, tom lane