Re: slow IN() clause for many cases

[Joe Conway <mail(at)joeconway(dot)com>]

Tom Lane wrote:
> Simon Riggs <simon(at)2ndquadrant(dot)com> writes:
>
> > Do you think we'll be able to generate a single ScalarArrayOpExpr from a
> > small subselect and pass it through as an indexable expression?
>
> If you don't mind spelling it with the ARRAY(sub-select) syntax, which
> I think is a Postgres-ism (though it's possible Joe got it from
> SQL2003).

It's in SQL 2003. See excerpt below.

Joe

6.36 <array value constructor>

Function

  Specify construction of an array.

Format

  <array value constructor> ::=
    <array value constructor by enumeration> |
    <array value constructor by query>
  <array value constructor by enumeration> ::=
    ARRAY <left bracket or trigraph>
          <array element list>
          <right bracket or trigraph>
  <array value constructor by query> ::=
    ARRAY <left paren>
          <query expression> [ <order by clause> ]
          <right paren>