| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
| Cc: | tushar <tushar(dot)ahuja(at)enterprisedb(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: pg_upgrade failed if view contain natural left join condition |
| Date: | 2017-07-20 16:14:06 |
| Message-ID: | 4181.1500567246@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> Per the docs:
> "If there are no common column names, NATURAL behaves like CROSS JOIN."
> I'm being a bit pedantic here but since NATURAL is a replacement for
> "ON/USING" it would seem more consistent to describe it, when no matching
> columns are found, as "behaves like specifying ON TRUE" instead.
Yeah, the analogy to CROSS JOIN falls down if it's an outer join.
I'll go fix that.
> I find it a bit strange, though not surprising, that it doesn't devolve to
> "ON FALSE".
No, it's normal that an AND of no conditions degenerates to TRUE.
It's like omitting a WHERE clause.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Jeff Janes | 2017-07-20 16:16:38 | Re: autovacuum can't keep up, bloat just continues to rise |
| Previous Message | Claudio Freire | 2017-07-20 16:08:55 | Re: Increase Vacuum ring buffer. |