Re: Index on array element

[sNip]
> It's got nothing to do with arrays as such, but is purely a syntactic
> restriction: if the indexed item is anything but an unadorned column
> name or a function call, CREATE INDEX wants parentheses around it.
>
> This is because the CREATE INDEX syntax also allows for an "operator
> class" name in there. Consider
>
> create index foodex on foo (bar ! ops);
>
> Is this supposed to mean indexing the expression "bar ! ops" (infix !
> operator) or indexing the expression "bar !" (postfix ! operator) using
> the operator class "ops"? No way to tell, so we make you clarify your
> intent with parentheses. You can say either
>
> create index foodex on foo ((bar ! ops));
> create index foodex on foo ((bar !) ops);
>
> depending which interpretation you want.

Thanks. Your explanation is very helpful.

--
Randolf Richardson - rr(at)8x(dot)ca
Vancouver, British Columbia, Canada

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