Re: Indexes on Expressions -- Parentheses

sszabo(at)bigpanda(dot)com

On Tue, 28 Sep 2004, Thomas F.O'Connell wrote:

> From 11.5 in the docs:
>
> "The syntax of the CREATE INDEX command normally requires writing
> parentheses around index expressions, as shown in the second example.
> The parentheses may be omitted when the expression is just a function
> call, as in the first example."
>
> But when I try this:
>
> db=# CREATE INDEX expression_idx on some_table( extract( year from
> some_column ) );

Extract(year from some_column) is not really just a function call it's
an expression that looks similar to a function call because that's how SQL
defined it.