Thanks Tom. This showed up in a regression test of ours that built the test
data using generate_series, so it's not a critical production issue or
anything, just a surprise change in behaviour.


On Wed, May 24, 2017 at 10:28 AM, Tom Lane <> wrote:

> Paul Ramsey <> writes:
> > The behaviour of generate_series seems to have changed a little, at least
> > in conjunction w/ CTEs.
> What's changed is the behavior of multiple SRFs in a SELECT's targetlist,
> cf
> 69f4b9c85f168ae006929eec44fc44d569e846b9
> specifically this comment:
>     While moving SRF evaluation to ProjectSet would allow to retain the old
>     "least common multiple" behavior when multiple SRFs are present in one
>     targetlist (i.e.  continue returning rows until all SRFs are at the
> end of
>     their input at the same time), we decided to instead only return rows
> till
>     all SRFs are exhausted, returning NULL for already exhausted ones.  We
>     deemed the previous behavior to be too confusing, unexpected and
> actually
>     not particularly useful.
> I see the current v10 release notes have failed miserably at documenting
> this :-(.  Will try to improve that.
>                         regards, tom lane

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