Re: Add generate_series(date,date) and generate_series(date,date,integer) - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Add generate_series(date,date) and generate_series(date,date,integer)
Date
Msg-id 16807.1456091547@sss.pgh.pa.us
Whole thread Raw
In response to Re: Add generate_series(date,date) and generate_series(date,date,integer)  (Christoph Berg <myon@debian.org>)
Responses Re: Add generate_series(date,date) and generate_series(date,date,integer)
List pgsql-hackers
Christoph Berg <myon@debian.org> writes:
> Re: David Fetter 2016-01-26 <20160126180011.GA16903@fetter.org>
>> +1 for back-patching.  There's literally no case where an infinite
>> input could be correct as the start or end of an interval for
>> generate_series.

> select * from generate_series(now(), 'infinity', '1 day') limit 10;
> ... seems pretty legit to me. If limit pushdown into SRFs happened to
> work some day, it'd be a pity if the above query raised an error.

Oooh ... actually, that works today if you consider the SRF-in-targetlist
case:

regression=# select generate_series(now(), 'infinity', '1 day') limit 10;       generate_series        
-------------------------------2016-02-21 16:51:03.303064-052016-02-22 16:51:03.303064-052016-02-23
16:51:03.303064-052016-02-2416:51:03.303064-052016-02-25 16:51:03.303064-052016-02-26 16:51:03.303064-052016-02-27
16:51:03.303064-052016-02-2816:51:03.303064-052016-02-29 16:51:03.303064-052016-03-01 16:51:03.303064-05
 
(10 rows)

Time: 8.457 ms

Given that counterexample, I think we not only shouldn't back-patch such a
change but should reject it altogether.
        regards, tom lane



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