Re: Backend-internal SPI operations

Jan Wieck <janwieck(at)Yahoo(dot)com> writes:
> From memory I think views are created as CREATE TABLE, with
> an internal DefineRuleStmt, and dumped as CREATE TABLE,
> CREATE RULE for sure. So the CREATE/DROP RULE would need to
> remove/recreate the tables file (plus toast file and index)
> if you want it to be consistent. Don't think you want that -
> do you?

But that's only true because it's such a pain in the neck for pg_dump
to discover that a table is a view. If this could easily be told from
inspection of pg_class, then it'd be no problem to dump views as
CREATE VIEW statements in the first place --- obviously better, no?

However the initial version upgrade would be a problem, since dump
files out of existing releases would contain CREATE TABLE & RULE
commands instead of CREATE VIEW. I guess what would happen is that
views reloaded that way wouldn't really be views, they'd be tables
with rules attached. Grumble.

How about this:
CREATE RULE of an on-select-instead rule changes table's
relkind to 'view'. We don't need to drop the underlying
table file, though (just leave it be, it'll go away at
next initdb).

DROP RULE of a view's on-select-instead is not allowed.
You have to drop the whole view instead.

regards, tom lane