Re: PoC: Make it possible to disallow WHERE-less UPDATE and DELETE

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Fetter <david@fetter.org>
Cc: PostgreSQL Development <pgsql-hackers@postgresql.org>
Date: 2016-07-21T13:49:33Z
Lists: pgsql-hackers
David Fetter <david@fetter.org> writes:
> Please find attached a patch which makes it possible to disallow
> UPDATEs and DELETEs which lack a WHERE clause.  As this changes query
> behavior, I've made the new GUCs PGC_SUSET.

> What say?

-1.  This is an express violation of the SQL standard, and at least the
UPDATE case has reasonable use-cases.  Moreover, if your desire is to have
training wheels for SQL, there are any number of other well-known gotchas
that are just as dangerous, for example ye olde unintentionally-correlated
subselect:
https://www.postgresql.org/message-id/20160714135233.1410.92538%40wrigleys.postgresql.org

I wouldn't have any objection to an extension that enforces rules like
these, but I don't think it belongs in core.

			regards, tom lane