Re: Remove mention in docs that foreign keys on partitioned tablesare not supported

On Mon, Jun 18, 2018 at 1:20 AM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
> That's a wrong comparison. Inheritance based partitioning works even
> after declarative partitioning feature is added. So, users can
> continue using inheritance based partitioning if they don't want to
> move to declarative partitioning. That's not true here. A user creates
> a BEFORE ROW trigger on each partition that mimics partitioned table
> level BEFORE ROW trigger. The proposed BEFORE ROW trigger on
> partitioned table will cascade the trigger down to each partition. If
> that fails to recognize that there is already an equivalent trigger, a
> partition table will get two triggers doing the same thing silently
> without any warning or notice. That's fine if the trigger changes the
> salaries to $50K but not OK if each of those increases salary by 10%.
> The database has limited ability to recognize what a trigger is doing.

I don't even know what to say about that.  You are correct that if a
user creates a new trigger on a partitioned table and doesn't check
what happens to any existing triggers that they already have, bad
things might happen.  But that seems like a pretty stupid thing to do.
If you make *any* kind of critical change to your production database
without testing it, bad things may happen.

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