Re: BUG #14016: Incomplete documentation of IN subquery expression

On Fri, Mar 11, 2016 at 10:02:01AM -0700, David G. Johnston wrote:
> On Fri, Mar 11, 2016 at 9:39 AM, <manlio(dot)perillo(at)gmail(dot)com> wrote:
>
> At the end of the documentation for VALUE (sql-values.html), there is the
> following tip:
> "For simple IN tests, it's better to rely on the list-of-scalars form of IN
> than to write a VALUES query as shown above"
>
> However there is no reference to the "list-of-scalars" forms of IN, in the
> functions-subquery.html page.  It is only reported that the supported
> syntax
> is "expression IN (subquery)"
>
> The reference was available in an old version (7.3), where the manual
> documented both the scalar form and sub query form:
> "expression IN (value[, ...])"
>
>
> ​It was moved...
>
> ​http://www.postgresql.org/docs/9.5/interactive/functions-comparisons.html#
> AEN20283
>
> ​The interpretation being that a "list of scalars" is, in this situation,
> semantically equivalent to an array - though having the later you would have to
> use "=ANY(array)" instead of "IN"
>
> ​Apparently someone disagreed with the note in the subquery section:
>
> >>>Note: This form of IN is not truly a subquery expression, but it seems best
> to document it in the same place as subquery IN.

Does the attached patch improve this?

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Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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