Re: Optimizing query

Hello Shridhar,

I use Matthew's solution and it works. Query takes only half a second. I
didn't know that i can index function to.

Thanks

Uros

Wednesday, November 19, 2003, 1:23:26 PM, you wrote:

SD> Uros wrote:

>> Hello!
>>
>> I have some trouble getting good results from my query.
>>
>> here is structure
>>
>> stat_views
>> id        | integer
>> id_zone   | integer
>> created   | timestamp
>>
>>
>> I have btree index on created and also id and there is  1633832 records in
>> that table
>>
>> First of all I have to manualy set seq_scan to OFF because I always get
>> seq_scan. When i set it to off my explain show:
>>
>> explain SELECT count(*) as views FROM stat_views WHERE id = 12;
>>                                              QUERY PLAN
>> ----------------------------------------------------------------------------------------------------
>>  Aggregate  (cost=122734.86..122734.86 rows=1 width=0)
>>    ->  Index Scan using stat_views_id_idx on stat_views
>> (cost=0.00..122632.60 rows=40904 width=0)
>>          Index Cond: (id = 12)
>>
>> But what I need is to count views for some day, so I use
>>
>> explain SELECT count(*) as views FROM stat_views WHERE date_part('day', created) = 18;
>>
>>                                      QUERY PLAN
>> ------------------------------------------------------------------------------------
>>  Aggregate  (cost=100101618.08..100101618.08 rows=1 width=0)
>>    ->  Seq Scan on stat_views  (cost=100000000.00..100101565.62 rows=20984 width=0)
>>          Filter: (date_part('day'::text, created) = 18::double precision)
>>
>>
>> How can I make this to use index and speed the query. Now it takes about 12
>> seconds.

SD> Can you post explain analyze for the same?

SD>   Shridhar