út 14. 7. 2020 v 0:37 odesílatel David G. Johnston < david.g.johns...@gmail.com> napsal:
> On Mon, Jul 13, 2020 at 2:12 AM Pavel Stehule <pavel.steh...@gmail.com> > wrote: > >> I am reading this patch. I don't think so text for domains and types are >> correct (or minimally it is little bit messy) >> This case is a little bit more complex - domains are not subset of >> relations. But relations (in Postgres) extends types. >> > > Yeah, though in further working on this I dislike the saying "A composite > type is a relation" (see Glossary and probably other spots). That a table > auto-creates a separate composite type, and depends on it, manifests a > certain link between the two but the type that represents the table is not > a relation as it doesn't hold data, it is just a definition. If a > composite type were a relation then whatever argument you use to justify > that would seem to apply to non-composite types as well. > > I'm attaching version 2 as a plain diff (complete) instead of a patch. > > New with this version is the addition of tests for drop domain and drop > type, and related documentation changes. Notably pointing out the fact > that DROP TYPE drops all types, including domains. > > To recap, the interesting relation related behaviors these tests > demonstrate are: > > A non-failure while performing a DROP "relation" IF EXISTS command means > that a subsequent CREATE "relation" command will not fail due to the name > already existing (other failures are of course possible). > > In the presence of multiple schemas a failure of a DROP "relation" IF > EXISTS command does not necessarily mean that an corresponding CREATE > "relation" command would fail - the found entry could belong to a non-first > schema on the search_path while the creation will place the newly created > object always on the first schema. > > The plain meaning of the opposite of "DROP IF EXISTS" (i.e., it's not an > error if the specified object doesn't exist, just move on) is not what > actually happens but rather we provide an additional test related to > namespace occupation that is now documented. > > The latter two items are explicitly documented while the first is implicit > and self-evident. > I think so now all changes are correct and valuable. I''l mark this patch as ready for commit Thank you for patch Regards Pavel > > David J. > >
