Query Cost
Hi,
I have a table with this schema:
CREATE TABLE billing.bill
(
sno serial NOT NULL,
billno int4,
det date NOT NULL,
.
.
.
CONSTRAINT bill_pkey PRIMARY KEY (sno)
)
I want to execute a query that will not return any record. Which of
these queries is cheaper please?
1. Select * from billing.bill where 1=0
2. Select * from billing.bill where sno=0
Thanks for your assistance.
Chris.
I can't find a reference in the docs for this...
I have a plperl function returning an int. The int is returned as the
result of a system call.
It is set to return a null if one of the inputs is null, but I can't see
how to return a null if the result is indeterminate. The function
currently returns a 0 instead.
How do I stick an if in the function to return a null where appropriate?
Thanks,
Brent Wood
Import Notes
Reply to msg id not found: 20050918220149.GX7630@pervasive.com
On Mon, Sep 19, 2005 at 10:52:23AM +1200, Brent Wood wrote:
I have a plperl function returning an int. The int is returned as the
result of a system call.It is set to return a null if one of the inputs is null, but I can't see
how to return a null if the result is indeterminate. The function
currently returns a 0 instead.How do I stick an if in the function to return a null where appropriate?
From the PL/Perl documentation:
"As shown above, to return an SQL null value from a PL/Perl function,
return an undefined value."
http://www.postgresql.org/docs/8.0/interactive/plperl.html
Is that what you're looking for?
--
Michael Fuhr