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Hmmm .... deamn ...

I have a realy big table (> 2'000'000 records). every second there are several inserts and updates. the thing is i need
alast row reference depending on a foreing_key. 
 

something like this:
id, foreign_key, last_id, value1, value1, date
>1<,           3,    null,     12,     13, 2007-01-01
>2<,           4,    null,     11,     10, 2007-01-01 4,           3,     >1<,     12,     13, 2007-01-02 5,
4,    >2<,     11,     10, 2007-01-02
 
...

of course the sequence can have holes so I have to calculate the real last row id. for now i calculate for each row by
invokinga "select max(id) where foreign_key = $1" but this cost a lot of performance. I could do this easily with one
updatefor the whole query - if i could know which foreign_key and which date range was performed.
 

any ideas?

thanks chris


On Thu, November 29, 2007 3:26 pm, Pavel Stehule wrote:
> On 29/11/2007, Stephen Cook <sclists@gmail.com> wrote:
>> I am curious (coming from a MS SQL Server background, I just started
>> playing with PostgreSQL recently).
> 
> yes, I belive. I was too. There are total different style of triggeres
> in Postgres. But If I can say, programming in Postgres is much more
> confortable. But It is different. You have to use ROW triggers.
> 
>>
>> What type of situation would warrant a statement-level trigger that
>> can't access the old and new values?  Without that access, isn't the
>> only information you get is the fact that an operation occurred on the
>> table?  Or am I missing something?
>>
>> -- Stephen
>>
> 
> Statement triggers can be used in some kind of auditing. Maybe. I
> didn't use it. And I use Postgres five years.
> 
> Pavel
>>
>>
>> Pavel Stehule wrote:
>> > Hello
>> >
>> > You cannot to access to values in statement trigger. Postgres doesn't
>> > support it.
>> >
>> > Regards
>> > Pavel Stehule
>> >
>> > On 29/11/2007, Christian Kindler <christian.kindler@gmx.net> wrote:
>> >> Hi
>> >>
>> >> Can anyone provide me a simple example of a statement-level trigger?
>> Problem is I do not know how to access the old.*, new.* values.
>> >>
>> >> Thanks
>> >> Chris
>> >> --
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-- 
cu
Chris

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