On Fri, Mar 29, 2013 at 11:02:54AM +0100, Budulinku Dejmihrasku wrote:

Hi, i hit a strange problem when using alias for an expression in group by i run into this with a complex view containing multiple UNION ALL queries but after a while everything boiled down to a fairly simple test case that will always produce the error

Welcome to mclient, the MonetDB/SQL interactive terminal
(Feb2013-SP1)
Database: MonetDB v11.15.3 (Feb2013-SP1), 'mapi:monetdb://
lux-analytics:50000/zkdev1'
Type \q to quit, \? for a list of available commands
auto commit mode: on
sql>CREATE VIEW mmtest_v AS SELECT date'2012-01-01' as period, 1 as
quantity;
operation successful (213.074ms)
sql>SELECT extract(month from period) as m, count(1) as cnt FROM
mmtest_v GROUP BY m;
Connection terminated

Could you create a bug report for this?

I am on Ubuntu 12.04.2 LTS As the alias in GROUP BY works in other cases i expect this is a bug - pls confirm and i will be happy to file it.

BTW it looks like MonetDB has generally issues with selects from more complex views - i.e. views based on another view(s). In such cases the results do not match expectations or there is even an error. I can reproduce the problem but i only on quite large set of data (typically 20+ mil. records) and after some data manipulation got involved, so i cannot give a simple test case as above. Any idea how to pass such problem (when large data-set is involved) to the development team?

Niels

Thanks in advance milan

---

users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

On 3/29/2013 11:36 AM, Stefan Manegold wrote:

...

On Fri, Mar 29, 2013 at 11:02:54AM +0100, Budulinku Dejmihrasku wrote:

...

Hi, i hit a strange problem when using alias for an expression in group by i run into this with a complex view containing multiple UNION ALL queries but after a while everything boiled down to a fairly simple test case that will always produce the error

 Welcome to mclient, the MonetDB/SQL interactive terminal
 (Feb2013-SP1)
 Database: MonetDB v11.15.3 (Feb2013-SP1), 'mapi:monetdb://
 lux-analytics:50000/zkdev1'
 Type \q to quit, \? for a list of available commands
 auto commit mode: on
 sql>CREATE VIEW mmtest_v AS SELECT date'2012-01-01' as period,
 1 as
 quantity;
 operation successful (213.074ms)
 sql>SELECT extract(month from period) as m, count(1) as cnt
 FROM
 mmtest_v GROUP BY m;
 Connection terminated

Could you create a bug report for this?

I can indeed reproduce the segfault --- thanks for reporting and providing this easy test!

Could you indeed please file a bug report including your example to reproduce the problem?

Could you then possibly also attach to the bug report the gdb trace I attach to this email? It shows the location and cause of the segfault.

done - *Bug 3264* http://bugs.monetdb.org/show_bug.cgi?id=3264

...

...

I am on Ubuntu 12.04.2 LTS As the alias in GROUP BY works in other cases i expect this is a bug - pls confirm and i will be happy to file it.

BTW it looks like MonetDB has generally issues with selects from more complex views - i.e. views based on another view(s). In such cases the results do not match expectations or there is even an error. I can reproduce the problem but i only on quite large set of data (typically 20+ mil. records) and after some data manipulation got involved, so i cannot give a simple test case as above. Any idea how to pass such problem (when large data-set is involved) to the development team?

It would be great if you could provide us --- preferably via bug report(s) --- as much information as possiblet to reproduce the problems, such that we can analyze them. For sharing large data sets (if possible; or data generators, if available), we'll need to find for each individual case a solution that is more suitable than attaching them to a bug report.

Stefan

ok - thanks hopefully we find time soon enough to prepare+scramble some data set to reproduce the issues i mentioned we are generally happy with MonetDB and this is the least we can do to help you improve :) milan

...

Niels

...

Thanks in advance milan _______________________________________________ users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

-- Niels Nes, Centrum Wiskunde & Informatica (CWI) Science Park 123, 1098 XG Amsterdam, The Netherlands room L3.14, phone ++31 20 592-4098 sip:4098@sip.cwi.nl url: http://www.cwi.nl/~niels e-mail: Niels.Nes@cwi.nl

---

users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list

---

users-list mailing list users-list@monetdb.org http://mail.monetdb.org/mailman/listinfo/users-list