Re: Same query, same performance

Josh,

> Alexandre,
>
>> I have a system with 7 Million of records in 600 tables.
>> My actual production machine is: P4 1.6G, 3 IDE 7200, 1GB PC133
>> My new machine production is: Dual Xeon 2.0G HT, 1GB DDR266 ECC
>> 3 SCSI with HW Raid 5
>
> Well, first of all, those two systems are almost equivalent as far as
> Postgres is concerned for simple queries.   The extra processor power
> will only help you with very complex queries.  3-disk RAID 5 is no
> faster ... and sometimes slower ... than IDE for database purposes.
>   The only real boost to the Xeon is the faster RAM ... which may not
> help you if your drive array is the bottleneck.

Today, I will add more one HD and I will make an RAID 10 ...
In next week i will report my tests to the list...

>
>>
>> The postgresql.conf is the SAME in both systems and I test
>> with no other connections, only my local test.
>>
>> shared_buffers = 80000
>> effective_cache_size = 60000
>> random_page_cost = 2.5
>> cpu_tuple_cost = 0.001
>> cpu_index_tuple_cost = 0.0001
>> cpu_operator_cost = 0.00025
>
> Not that it affects the query below, but what about SORT_MEM?

Sort_mem = 32000

> Actually, from your stats, Postgres is doing a pretty good job.   1.18
> seconds to return 15 rows from a 7 million row table searching on not
> Indexed columns?  I don't think you have anything to complain about.

The table have 300000 tuples, the entire database have 7 million.
Tomazs answer the question: a missing index on fn06t ...

But the query time difference of the systems continue.
I will change the discs and tell to list after...

Thank´s Josh,


Alexandre