Re: Truncate if exists

On Mon, Oct 15, 2012 at 3:14 PM, Dimitri Fontaine
<dimitri(at)2ndquadrant(dot)fr> wrote:
> What about continuing to extend on that incredibly useful WITH syntax we
> already have:
>
> WITH target AS (
> SELECT oid::regclass AS t
> FROM pg_class c JOIN pg_namespace n ON c.relnamespace = n.oid
> WHERE pg_table_is_visible(oid)
> AND nspname = 'public' AND NOT relname ~ 'exclude-pattern'
> )
> TRUNCATE TABLE t FROM target;

I'm not exactly sure what that is supposed to do, but it doesn't seem
like an easy-to-use substitute for truncate-if-exists...

>> my view the goal ought to be to refine that mechanism to remove the
>> clunkiness and awkwardness, rather than to invent something completely
>> new.
>
> So, what do you think? Smells like empowered SQL this time, right?

I like the idea of making our SQL dialect capable of working with DDL
in more powerful ways; I'm not sold on the concrete proposal.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company