Tom Lane wrote:
Patrice Beliveau <pbeliveau@xxxxxxxx> writes:
SELECT * FROM TABLE
WHERE TABLE.COLUMN1=something
AND TABLE.COLUMN2=somethingelse
AND function(TABLE.COLUMN3,TABLE.COLUMN4) > 0;
I find out that the function process every row even if the row should be
rejected as per the first or the second condition.
... I'm using version 8.1.3
PG 8.1 will not reorder WHERE clauses for a single table unless it has
some specific reason to do so (and AFAICT no version back to 7.0 or so
has done so either...) So there's something you are not telling us that
is relevant. Let's see the exact table schema (psql \d output is good),
the exact query, and EXPLAIN output for that query.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
Hi,
here is my query, and the query plan that result
explain select * from (
select * from sales_order_delivery
where sales_order_id in (
select sales_order_id from sales_order
where closed=false
)
) as a where outstandingorder(sales_order_id, sales_order_item,
date_due) > 0;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
Hash IN Join (cost=498.89..8348.38 rows=34612 width=262)
Hash Cond: (("outer".sales_order_id)::text =
("inner".sales_order_id)::text)
-> Seq Scan on sales_order_delivery (cost=0.00..6465.03 rows=69223
width=262)
Filter: (outstandingorder((sales_order_id)::text,
(sales_order_item)::text, date_due) > 0::double precision)
-> Hash (cost=484.90..484.90 rows=5595 width=32)
-> Seq Scan on sales_order (cost=0.00..484.90 rows=5595 width=32)
Filter: (NOT closed)
(7 rows)
