Re: [PATCH] Add pg_get_table_ddl() to reconstruct CREATE TABLE statements

The previous features all look good to me, I only have one question
for the new flag.

> Calling
> pg_get_table_ddl(t, 'includes_foreign_keys', 'false') now emits everything
> except FOREIGN KEY constraints. This covers the multi-tenant clone
> workflow: create tables first without cross-table references, then re-run
> with the default to add the constraints once all targets exist.

I think this feature needs a bit more documentation, an
"only_foreign_keys" flag, or both.

CREATE TABLE refd (id int PRIMARY KEY);
CREATE TABLE cons (a int CHECK(a>0), b int UNIQUE, c int REFERENCES refd(id));

-- pass 1: running without foreign keys
SELECT * FROM pg_get_table_ddl('cons','includes_foreign_keys','false');
-- execute everything

-- loading data

-- pass 2: running with everything
SELECT * FROM pg_get_table_ddl('cons','includes_foreign_keys','true');
-- ERROR: relation "cons" already exists (and the unique constraint
also collides)

I could do a "grep FOREIGN KEY" before executing (unless it's a tricky
schema where that phrase appears elsewhere), or since psql continues
on error, it will simply work if I accept a significant error noise,
but then the documentation should be clear about this limitation.
Following the documented approach and getting a bunch of unexpected
errors could be confusing for users.