On Tue, Jan 07, 2003 at 03:10:06PM -0800, Dann Corbit wrote:
> NOTICE: QUERY PLAN:
>
> SetOp Except (cost=202028537.97..202120623.90 rows=1227812 width=24)
> -> Sort (cost=202028537.97..202028537.97 rows=12278124 width=24)
> -> Append (cost=100000000.00..200225099.24 rows=12278124
> width=24)
> -> Subquery Scan *SELECT* 1
> (cost=100000000.00..100112549.62 rows=6139062 width=24)
> -> Seq Scan on CNX_DS_53_SIS_STU_OPT_FEE_TB a
> (cost=100000000.00..100112549.62 rows=6139062 width=24)
> -> Subquery Scan *SELECT* 2
> (cost=100000000.00..100112549.62 rows=6139062 width=24)
> -> Seq Scan on CNX_DS2_53_SIS_STU_OPT_FEE_TB b
> (cost=100000000.00..100112549.62 rows=6139062 width=24)
>
> EXPLAIN
Those big round numbers suggest that you haven't run vacuum analyze on
all of your tables. Since PostgreSQL uses a cost-based optimizer, you
do actually have to give it some idea of what things will cost before
it can give you an appropriate plan.
Reference for your version:
http://www14.us.postgresql.org/users-lounge/docs/7.1/reference/sql-vacuum.html
-johnnnnnnnnn