Hello
one my customer reported following problem (checked on 8.4 and 8.3.6)
test case:
create table test(a integer);
create or replace function getid(_a integer) returns integer as $$
begin update test set a = _a where a = _a; return _a;
end;
$$ language plpgsql;
insert into test values(20);
select * from test where a = 20; --> one row
select getid(20); --> 20
the problem:
postgres=# delete from test where a = getid(20);
DELETE 0
Time: 1,510 ms
but
postgres=# explain analyze delete from test where a = getid(20); QUERY PLAN
-------------------------------------------------------------------------------------------------Seq Scan on test
(cost=0.00..640.00rows=12 width=6) (actual
time=0.149..0.154 rows=1 loops=1) Filter: (a = getid(20))Total runtime: 0.221 ms
(3 rows)
explain analyze signalise one deleted row, but this is not true
regards
Pavel Stehule