Hi Frederic

Thank you for your interest and (private) enhancements of the MonetDB code base.
Would be nice to share some of those to the community if relevant for a larger
audience. Pushing a piece of technology that large and complex is a challenge
for all involved.

Your bugreport will be taken up in the next round of software improvements.
It seems you retract the creation of 'foo' by releasing the savepoint record,
dropping it from further consideration. Clearly, you won't find it anymore.
Enhanced savepoint management is on our list of 'unsupported' features.
https://www.monetdb.org/Documentation/Manuals/SQLreference/Features/unsupported

Your request puts it into view for re-consideration.

You can have a look at the extensive regression testing that takes place
on a daily basis and covers both functional and user supplied bug reports.
https://www.monetdb.org/Developers/NightlyTesting

For business urgent issues you can always contact MonetDB Solutions
to find a solution for your problem.

regards, Martin Kersten

On 18/06/15 10:44, Frédéric Jolliton wrote:

Greetings,

We filled a bug few days ago about simple SAVEPOINT usage corrupting the
database (both in Oct2014-SP4 and tip of hg). This is worrying us a
lot, because that's yet another bug easy to trigger.

We're studying MonetDB extensively for our future needs. We've written
optimizers, custom aggregate functions in C, and we've studied many
internal aspects.

But yet, from time to time, we are hit by bugs when performing simple,
trivial queries. You can see the history of bugs we filled on the
bugtracker (regarding UNION, SELECT, ..). This become time consuming.

This make us nervous because we might have hard time trusting our
complexes queries run by MonetDB.

The performance are stunning, but the quality seems not high enough for
production. Projects like PostgreSQL shows that even Open Source
projects can attains incredible stability and robustness. (Admittedly
there are many more contributors to PostgreSQL.)

Note that we understand that it is a complex software, and that it is
hard to cover all possible corner cases in tests.

But we're wondering how stable MonetDB is expected to be. Is this really
used in production?

Regarding the MonetDB website, the primary source of information for the
project, we've not found any reference documentation regarding all the
supported SQL features. Sure, there is a page listing what is *not*
supported, there are pages on various topics, but it is unclear if
SAVEPOINT is really supported. (If I can say, I think that the website
probably needs some refresh and better navigation.)

Here is the latest bug I was talking about:

     $ bin/mclient -p 50005 test
     Welcome to mclient, the MonetDB/SQL interactive terminal (Oct2014-SP4)
     Database: MonetDB v11.19.13 (Oct2014-SP4), 'mapi:monetdb://fjolliton:50005/test'
     Type \q to quit, \? for a list of available commands
     auto commit mode: on
     sql>start transaction;
     auto commit mode: off
     sql>create table foo (a int);
     operation successful (0.528ms)
     sql>savepoint sp1;
     auto commit mode: off
     sql>release savepoint sp1;
     auto commit mode: off
     sql>commit;
     auto commit mode: on
     sql>select * from foo;
     +---+
     | a |
     +===+
     +---+
     0 tuples (0.9s)

So far, so good. Now try to connect again:

     $ bin/mclient -p 50005 test
     Welcome to mclient, the MonetDB/SQL interactive terminal (Oct2014-SP4)
     Database: MonetDB v11.19.13 (Oct2014-SP4), 'mapi:monetdb://fjolliton:50005/test'
     Type \q to quit, \? for a list of available commands
     auto commit mode: on
     sql>select * from foo;
     SELECT: no such table 'foo'

Whoops !

Regards,

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