> I don't think your idea would work for a concurrent user setup where
> people have different transactions started at different times with
> different amounts of changes inside each transaction.
>
> That's why it would have to be tracked on a "per connection" basis for
> all the tables.
I tried it out with concurrent connections and it seemed to hold up just
fine. I think MVCC took care of everything. Transactions got a different
count depending on whether they could see the inserted values or not. Once
committed all transactions could see the new table count.
Can you provide a case where it wouldn't?
I imagine this causes some major performance issues, not to mention the dead
tuples would pile up fast, but it seems to work just fine.
My SQL is below.
Regards,Jeff
jdavis=> create table tuple_count(tuples int);
CREATE
jdavis=> create table c1(a int);
CREATE
jdavis=> create function f1() returns opaque as '
jdavis'> BEGIN
jdavis'> UPDATE tuple_count set tuples=tuples+1;
jdavis'> RETURN NEW;
jdavis'> END;
jdavis'> ' language 'plpgsql';
CREATE
jdavis=> create function f2() returns opaque as '
jdavis'> BEGIN
jdavis'> UPDATE tuple_count set tuples=tuples-1;
jdavis'> RETURN NEW;
jdavis'> END;
jdavis'> ' language 'plpgsql';
CREATE
jdavis=> create trigger t1 after insert on c1 for each row execute procedure
f1();
CREATE
jdavis=> create trigger t2 after delete on c1 for each row execute procedure
f2();
CREATE
