Re: Window Functions: v07 APIs and buffering strateties

Hitoshi Harada Wrote:

> As I promised, version 7 of the window functions is now released. At
> the same time, git repository branch comes back to master.
>
> git: http://git.postgresql.org/?p=~davidfetter/window_functions/.git
> patch: http://umitanuki.net/pgsql/window_functions.patch.20081028.gz

I've been testing for a couple of hours now and just comparing results to
the results Oracle gives me. Perhaps not the best method but it's faster
than reading through the spec.

I managed to get a seg-fault with the following query.

select salary,dense_rank() over (order by salary desc)
from employee
group by salary;


It's the group by that does it.

test=# select salary,dense_rank() over (order by salary desc) from employee
group by salary;
server closed the connection unexpectedly       This probably means the server terminated abnormally       before or
whileprocessing the request. 
The connection to the server was lost. Attempting reset: Failed.


It seems to be possible to crash not just dense_rank() and rank().

This crashes too.

select relid,AVG(seq_Scan) OVER (ORDER BY relid)
FROM pg_stat_user_tables
GROUP BY relid,seq_scan;

Oracle allows both these queries.

Of course I changed table names and column names to make the test case a bit
easier to re-produce.

Looking forward to seeing windowing functions in 8.4!

David