Hi!
Thanks for your help!
On Tue, 23 Jul 2002, Gaetano Mendola wrote:
>"Daryl Herzmann" <akrherz@iastate.edu> wrote:
>> snet=# select count(valid) from t2002_06;
>> count
>> ---------
>> 1513895
>
>> snet=# explain SELECT * from t2002_06 WHERE station = 'SGLI4';
>> NOTICE: QUERY PLAN:
>>
>> Seq Scan on t2002_06 (cost=0.00..35379.69 rows=35564 width=47)
>
>
>Can you do the following query for better understand your situation ?
>
>select count(*) from t2002_06 where station = 'SGLI4';
snet=# select count(*) from t2002_06 where station = 'SGLI4';count
-------39319
>select count(*) from t2002_06;
snet=# select count(*) from t2002_06; count
---------1513895
In another email, it was suggested that I do this...
snet=# explain analyze select * from t2002_06 WHERE station = 'SAMI4';
NOTICE: QUERY PLAN:
Seq Scan on t2002_06 (cost=0.00..35379.69 rows=34979 width=47) (actual
time=67.89..3734.93 rows=38146 loops=1)
Total runtime: 3748.33 msec
EXPLAIN
snet=# set enable_seqscan=off;
SET VARIABLE
snet=# explain analyze select * from t2002_06 WHERE station = 'SAMI4';
NOTICE: QUERY PLAN:
Index Scan using t2002_06_station_idx on t2002_06 (cost=0.00..132124.96
rows=34979 width=47) (actual time=72.03..298.85 rows=38146 loops=1)
Total runtime: 317.76 msec
EXPLAIN
Thanks so much! Daryl
