Re: slow IN() clause for many cases - Mailing list pgsql-hackers

Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.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>
<arrayvalue constructor by enumeration> ::=    ARRAY <left bracket or trigraph>          <array element list>
<rightbracket or trigraph>  <array value constructor by query> ::=    ARRAY <left paren>          <query expression> [
<orderby clause> ]          <right paren>