Indexes on Expressions -- Parentheses

[Thomas F.O'Connell]

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 ) );

I get a syntax error corresponding to the open parenthesis after
extract (and whitespace is not the issue).

If I add an enclosing set of parentheses, E.g.:

db=# CREATE INDEX expression_idx on some_table( ( extract( year from
some_column ) ) );

it works!

Is this a known issue?

-tfo

[Stephan Szabo]

ss****@bigpanda.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.
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match