Re: SELECT INTO deprecation

On 12/15/20 5:13 PM, Bruce Momjian wrote:
> On Wed, Dec  9, 2020 at 09:48:54PM +0100, Peter Eisentraut wrote:
>> On 2020-12-03 20:26, Peter Eisentraut wrote:
>> > On 2020-12-03 16:34, Tom Lane wrote:
>> > > As I recall, a whole lot of the pain we have with INTO has to do
>> > > with the semantics we've chosen for INTO in a set-operation nest.
>> > > We think you can write something like
>> > > 
>> > >      SELECT ... INTO foo FROM ... UNION SELECT ... FROM ...
>> > > 
>> > > but we insist on the INTO being in the first component SELECT.
>> > > I'd like to know exactly how much of that messiness is shared
>> > > by SQL Server.
>> > 
>> > On sqlfiddle.com, this works:
>> > 
>> > select a into t3 from t1 union select a from t2;
>> > 
>> > but this gets an error:
>> > 
>> > select a from t1 union select a into t4 from t2;
>> > 
>> > SELECT INTO must be the first query in a statement containing a UNION,
>> > INTERSECT or EXCEPT operator.
>> 
>> So, with that in mind, here is an alternative proposal that points out that
>> SELECT INTO has some use for compatibility.
> 
> Do we really want to carry around confusing syntax for compatibility?  I
> doubt we would ever add INTO now, even for compatibility.
> 

If memory serves the INTO syntax is a result from the first incarnation 
of PL/pgSQL being based on the Oracle PL/SQL syntax. I think it has been 
there from the very beginning, which makes it likely that by now a lot 
of migrants are using it in rather old code.

I don't think it should be our business to throw wrenches into their 
existing applications.


Regards, Jan

-- 
Jan Wieck
Principle Database Engineer
Amazon Web Services