Trigger efficiency

Hi,

I've the following problem and I don't know how to solve it: There is a 
table with about 10-12 fields, a couple of those fields are updated very 
often (about 30 times / minute or even more). This is my table (more or 
less):

crete table monitor(   time Timestamp,   time2 timestamp,   ...   status int,
);

I need to know how many rows are in the table and keep that number to 
another table every time that there is an INSERT or DELETE on that 
table, so I made a trigger that fires on insert and delete events and 
calls a function that makes de update on the new table, that works well. 
My problem starts when I have to count the rows depending on the status 
field: I added a UPDATE on my trigger and it works! :)...... my trigger:

CREATE TRIGGER tr_barra_aps AFTER INSERT OR DELETE OR UPDATE   ON monitor EXECUTE PROCEDURE f_barra_aps();

But now, this trigger fires too often and there is an extra load on the 
system that makes everything run slower. I posted before a question 
asking about firing triggers on specific columns...thats not possible. I 
don't know how to solve it, perhaps I should do it without 
triggers.....any help will be appreciated

thanks!

-- 
Josep Sanmarti
Analista de Projectes

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