On Sat, Mar 1, 2014 at 2:11 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > > Fabrízio de Royes Mello <fabriziomello@gmail.com> writes: > > On Sat, Jan 18, 2014 at 11:12 PM, Stephen Frost <sfrost@snowman.net> wrote: > >> Fabrízio, can you clarify the use-case for things like CREATE AGGREGATE > >> to have IF NOT EXISTS rather than OR REPLACE, or if there is a reason > >> why both should exist? Complicating our CREATE options is not something > >> we really wish to do without good reason and we certainly don't want to > >> add something now that we'll wish to remove in another version or two. > > > Well I have a scenario with many servers to deploy DDL scripts, and most of > > them we must run without transaction control because some tasks like CREATE > > INDEX CONCURRENTLY, DROP/CREATE DATABASE, CLUSTER, etc. > > > When an error occurs the script stops, but the previous commands was > > commited, then we must review the script to comment parts that was already > > executed and then run it again. Until now is not a really trouble, but in > > some cases we must deploy another DDL script that contains a new version of > > some object before we finish to fix the previous version that was in > > production, and if we have CINE for all CREATE objects this task will more > > easy because we just run it again without care if will replace the content > > and do not produce an error. > > Why wouldn't COR semantics answer that requirement just as well, if not > better? >
Just because it will replace the object content... and in some cases this cannot happen because it will regress the schema to an old version.
I know it's a very specific use case, but in a scenario with many servers and many automated tasks in different pipelines, CINE will be very useful. I have this kind of troubles mostly with functions (we use COR), and sometimes we will discover that the production version of function is wrong after we receive a user notify, and in this situation many times we spend a lot of effort do fix the whole damage.
