Using pg 7.2.1
If I have a simple table transfer
company_id int,
module character(2)
otherfields ...
and an index
CREATE INDEX transfer_5 on transfer(company_id,module);
with the query
explain select * from transfer where company_id=1012 order by
company_id,module desc;
I get ..
NOTICE: QUERY PLAN:
Sort (cost=462.74..462.74 rows=117 width=176)
-> Index Scan using transfer_5 on transfer (cost=0.00..458.71
rows=117 width=176)
Other info ..
select count(*) from transfer where company_id=1012;
count
-------
5264
(1 row)
import=# select count(*) from transfer;
count
-------
23481
(1 row)
Why does it have to sort it? The desc is at the end and the first
argument is constant. Is there some way I can force postgres to read the
index backwards and save the sort step?
