Re: count with high allocation

paulo matadr <saddoness@yahoo.com.br> writes:
> Monitoring "top" in database server  , i could  noticed an query with reserved  8GB on physical memory.

> select count(field) from big_table  1 inner join big_table2...

> There is the possibility of using another function with less memory allocation?
> Is there a way to limit the memory usage of the count?

It seems quite likely that what top is telling you just reflects the
process touching all shared buffers, and has nothing to do with any
real "memory consumption".  What do you have shared_buffers set to?

            regards, tom lane