Hi,
we have a large export here, I made an in-house benchmark
between Informix, plain PostgreSQL-8.1.4 and
8.2devel+COPY(SELECT) using the same data and query.
Find the results below for the two PostgreSQL versions.
With PostgreSQL 8.1.4, I used this:
begin;
select ... into temp myquery1;
copy myquery1 to stdout csv delimiter '|';
rollback;
With 8.2devel, I simple used
copy (select ...) to stdout csv delimiter '|';
# of clients: 1* 3** 10**
PostgreSQL 1:33 10:58 55:46
PostgreSQL 8.2 1:19 4:55 18:28
* - average of 4 runs, the first was with cold caches after reboot
** - 1 run, average of cliens' runtimes
Performance between 8.1.4 and 8.2devel is interesting:
1 client: 15%
3 clients: 55.2%
10 clients: 66.9%
The same machine was used for testing.
Best regards,
Zoltán Böszörményi
