Re: PERFORMANCE and SIZE

Ha !

No - it didn't catch me -- but Yes my spam has been going through the
roof lately.
Over here in Australia it's in the Media alot of late - Spam increases.
Seems like everyone is suffering.

Cheers
RS.

Bruce Momjian wrote:

>I have gotten so much spam, this subject line struck me as spam until I
>looked closer. Did it catch anyone else?
>
>---------------------------------------------------------------------------
>
>Alfranio Junior wrote:
>
>
>> Hello,
>>
>>I'm a new PostgresSql user and I do not know so much about the
>> performance mechanisms currently implemented and available.
>>
>> So, as a dummy user I think that something strange is happening with me.
>> When I run the following command:
>>
>> explain analyze select * from customer
>> where c_last = 'ROUGHTATION' and
>> c_w_id = 1 and
>> c_d_id = 1
>> order by c_w_id, c_d_id, c_last, c_first limit 1;
>>
>> I receive the following results:
>>
>> (Customer table with 60.000 rows) -
>> QUERY PLAN
>> ---------------------------------------------------------------------------
>>-----------------------------------------------------------
>> Limit (cost=4.84..4.84 rows=1 width=283) (actual time=213.13..213.13
>> rows=0 loops=1)
>> -> Sort (cost=4.84..4.84 rows=1 width=283) (actual
>> time=213.13..213.13 rows=0 loops=1)
>> Sort Key: c_w_id, c_d_id, c_last, c_first
>> -> Index Scan using pk_customer on customer (cost=0.00..4.83
>> rows=1 width=283) (actual time=211.93..211.93 rows=0 loops=1)
>> Index Cond: ((c_w_id = 1) AND (c_d_id = 1))
>> Filter: (c_last = 'ROUGHTATION'::bpchar)
>> Total runtime: 213.29 msec
>> (7 rows)
>>
>>
>> (Customer table with 360.000 rows) -
>> QUERY PLAN
>> ---------------------------------------------------------------------------
>>-------------------------------------------------------------
>> Limit (cost=11100.99..11101.00 rows=1 width=638) (actual
>> time=20.82..20.82 rows=0 loops=1)
>> -> Sort (cost=11100.99..11101.00 rows=4 width=638) (actual
>> time=20.81..20.81 rows=0 loops=1)
>> Sort Key: c_w_id, c_d_id, c_last, c_first
>> -> Index Scan using pk_customer on customer
>> (cost=0.00..11100.95 rows=4 width=638) (actual time=20.40..20.40 rows=0
>> loops=1)
>> Index Cond: ((c_w_id = 1) AND (c_d_id = 1))
>> Filter: (c_last = 'ROUGHTATION'::bpchar)
>> Total runtime: 21.11 msec
>> (7 rows)
>>
>> Increasing the number of rows the total runtime decreases.
>> The customer table has the following structure:
>> CREATE TABLE customer
>> (
>> c_id int NOT NULL ,
>> c_d_id int4 NOT NULL ,
>> c_w_id int4 NOT NULL ,
>> c_first char (16) NULL ,
>> c_middle char (2) NULL ,
>> c_last char (16) NULL ,
>> c_street_1 char (20) NULL ,
>> c_street_2 char (20) NULL ,
>> c_city char (20) NULL ,
>> c_state char (2) NULL ,
>> c_zip char (9) NULL ,
>> c_phone char (16) NULL ,
>> c_since timestamp NULL ,
>> c_credit char (2) NULL ,
>> c_credit_lim numeric(12, 2) NULL ,
>> c_discount numeric(4, 4) NULL ,
>> c_balance numeric(12, 2) NULL ,
>> c_ytd_payment numeric(12, 2) NULL ,
>> c_payment_cnt int4 NULL ,
>> c_delivery_cnt int4 NULL ,
>> c_data text NULL
>> );
>>
>> ALTER TABLE customer ADD
>> CONSTRAINT PK_customer PRIMARY KEY
>> (
>> c_w_id,
>> c_d_id,
>> c_id
>> );
>>
>> Does anybody know what is happening ?
>>
>>
>> Thanks !!!!
>>
>> Alfranio Junior
>>
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 5: Have you checked our extensive FAQ?
>>
>>http://www.postgresql.org/docs/faqs/FAQ.html
>>
>>
>>
>
>
>