Alexander Korotkov <aekorotkov(at)gmail(dot)com> writes:
> I found that results of previous tests with USNOA2 were not fully correct.
> Tables for tests with various parameters contained tuples in different
> order. I assumed that query
> CREATE TABLE tab2 AS (SELECT * FROM tab1);
> creates tab2 as exact copy of tab1, i.e. tab2 contain tuples in same order
> as tab1. But actually, it isn't always so. In aggregate with only few used
> test cases it can cause significant error.
For test purposes, you could turn off synchronize_seqscans to prevent
that.
regards, tom lane