[Monetdb-developers] next release: mps or algebra?

Martin Kersten Martin.Kersten at cwi.nl
Tue Oct 16 23:18:21 CEST 2007


Good to see this discussion. Although the topic is primarily 
MonetDB/XQuery it is good
to keep an eye on the global picture. Releases include more stuff and 
requires a lot of
time to prepare. (the release itself easily consumes several months of 
full time work,
many delivered by free (weekend) time!!!!)
Good planning and long-term internal use are a prerequisite.
Something we still have to learn.
Once the release cycle starts, the train can not stop and full power 
be in the hands of a single person. The release manager currently is Sjoerd,
one of the project admins!

As soon as a RC is available, those with a non-standard platform 
(windows, sun,
mac, vista) should immediately double check to assure it basically works.
This holds for all addressed and developers.

In this respect, the time frame mentioned below is overly optimistic. 
Anyone close to
the core group should work on the HEAD to help uncover problems from day 1.
Code changes should *not* be collected by individual programmers until
release time .
This is a major source of frustration, because you simply may not expect
your team members to spent day and night to fight the 'last' bugs. Let 
alone to
quick-test your latest feature or performance improvement.
PLEASE, check-in daily your changes and make sure you have at least ran
mtest on your platform. And most of all, know that your changes are
scrutinized for potential quality problems by others. It is the best way
to avoid many bugs.

Furthermore, changes in the interfaces visible to users and the effect 
on their databases
should be kept to a minimum. Backward compatibility is a must as long as 
it is manageable.
Beware that a change in storage structure may help a few extreme users, 
but may affects
hundreds or thousands in their daily use. E.g. one of our users would 
have to unload/reload
a 0.5Tb business critical application.

MonetDB/Query and MonetDB/SQL are intertwined. This creates responsibility
both ways.

Peter Boncz wrote:
> Stefan suggested rightly to move this discussion to the mailing list.
> I also changed the language into english for that purpose.
> Maurice' original questions were:
> (a) whether the new release would be algebra-only (short answer: hopefully).
In my opinion this can only be answered if the algebra version, in its 
full glory (without mps)
is used for several months internally, e.g. using students for stress 
> (b) whether our talk of a new release also refers to submodules, such as
> probxml and pftijah (short answer: yes)
Submodules basically follow their own release cycle. Regardless the 
source, e.g. datacells
geom, ....  Keeping in line is the responsibility of their owners, and 
the core developers
should be aware that their changes may break the work of others. Or at 
least drain a
possibly substantial amount of time.
> (c) whether all issues on the wiki, see:
> http://www.pathfinder-xquery.org/wiki/index.php/Jupiter:_The_Algebra_Release
>     needed for this action, have already been resolved (short answer: no)
The pathfinder wiki is a good example of team documentation.

I am looking forward to the upcoming release. The next one might be this 
but not necessarily includes everything on the drawing board.

regards, Martin
> On Tue, Oct 16, 2007 at 05:23:43PM +0200, Peter Boncz wrote:
>> Hi Maurice, et al,
>> The release of (hopefully) this week will still be mps based. I also
>> anticipate at least one bug-fix release (ie 0.20.2), or even more.  However,
>> the next major release (0.22) should be algebra based, in my opinion. I am
>> certainly reluctant to keep investing any more effort in mps. I would aim
>> for an mps-free release, yes.
>> The time-goal of that release is "XMAS 2007", as far as we are concerned.
>> For the work of built-in functions I have good hope that with the help of
>> Lefteris we can come a long way.
>> I hope and think updates can also be ported by joerd in that time-frame. As
>> for pftijah, if Jan Flokstra has time, it should be possible to port that as
>> well in 2-3 months.
>> There are some hairy issues, one of them being free-form recursion (needed
>> by you), another one being precompiled modules (needed by XRPC). The
>> resolution of these needs assistance from Munich, and maybe related. It needs
>> a method to compile certain functions into scripted procedures (here MIL)
>> and calling them. One algorithm is to do this for all functions in modules,
>> as well as for all recursive functions. The issue to resolve is the
>> representation of the parameters.
>> Depending on how much time Jan Rittinger has available for this, we will
>> have to find creative solutions for this. Indeed, a backup solution would be
>> to keep handling certain queries for the time being with mps, but that
>> surely is ugly.
>> Peter
>>   -----Original Message-----
>>   From: Keulen, M. van (Maurice) [mailto:m.vankeulen at utwente.nl]
>>   Sent: dinsdag 16 oktober 2007 16:38
>>   To: Peter Boncz [CWI]; Stefan Manegold [CWI]
>>   Cc: Djoerd Hiemstra; Jan Flokstra; Henning Rode; Abdel Kader, R. (Riham)
>>   Subject: Nieuwe releases en mps-backend
>>   Hoi,
>>   Sorry dat ik niet bij de Skype-sessie van vandaag kon zijn, maar Riham
>> vertelde me dat het onderwerp van nieuwe releases en de mps-backend ter
>> sprake is geweest. Het riep wat specifieke vragen bij me op die ze niet
>> allemaal kon beantwoorden:
>>     a.. Is het de bedoeling dat een nieuwe release de mps-backend helemaal
>> niet meer bevat of alleen maar de algebra-backend als default heeft?
>>     b.. Als jullie praten over "nieuwe release", bedoel je dan alleen een
>> package van alle modules van MonetDB/XQuery? Maw zegt het niets over
>> eventuele `subreleases' van individuele modules?
>>     c.. Op de wiki hebben we een pagina met open issues voor de
>> algebra-release. Wat is de status van die open issues? Ik zie namelijk op de
>> pagina nergens dat bepaalde issues al opgelost/geïmplementeerd zijn.
>>   Ik Cc deze e-mail even aan de PF/Tijah-mensen, want  hoewel er levendige
>> discussies zijn hoe PF/Tijah naar de algebra-backend to porten, ik heb niet
>> het idee dat er oplossingen zijn die op korte termijn realiseerbaar zijn.
>> Evenzo het recursie-vraagstuk. Het lijkt me bijvoorbeeld voor de
>> zichtbaarheid naar buiten toe onwenselijk als deze features ineens zouden
>> wegvallen voor non-insiders. Of andere onwenselijke consequenties van het
>> niet meer (sub)releasen van modules die gebaseerd zijn op de mps-backend.
>>   Groetjes,
>>   Maurice.
>> --
>> ----------------------------------------------------------------------
>> Dr.Ir. M. van Keulen - Assistant Professor, Data Management Technology
>> Univ. of Twente, Dept of EEMCS, POBox 217, 7500 AE Enschede, Netherlands
>> Email: m.vankeulen at utwente.nl, Phone: +31 534893688, Fax: +31 534892927
>> Room: ZI 3039, WWW: http://www.cs.utwente.nl/~keulen

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