Обсуждение: [GSoC] Optimization tasks
Hello,
My name is Camelia, I carry out Doctoral/PhD research in the field of database query processing and I'd like to contribute with PostgreSQL optimization tasks during this year's GSoC:
- Optimization- add to the join removal code the ability to remove joins to tables when the join is on a foreign key column (where all entries must exist in the parent anyway)
- Optimization- Check the set of conditionals on a WHERE clause against CHECK constraints on the table being queried and remove any conditionals which *must* be true due to the CHECK constraints
and others that may appear interesting along my review of the source code.
I'm very excited about this opportunity and I hope that the results will be as good!
Will the aforementioned subjects be open for work or do other committers have them under work already?
Do you have a specific template for the project proposal?
Thank you very much!
Best regards,
CameliaHello,
For my second question, I guess that [1] provides the information of the expected parts of the project proposal.Have a nice week-end,
Camelia[1] http://www.postgresql.org/developer/summerofcode/#proposals
---------- Forwarded message ----------
From: Camelia C <camelia13c@gmail.com>
Date: Thu, Mar 5, 2015 at 3:54 AM
Subject: [GSoC] Optimization tasks
To: pgsql-students@postgresql.org
From: Camelia C <camelia13c@gmail.com>
Date: Thu, Mar 5, 2015 at 3:54 AM
Subject: [GSoC] Optimization tasks
To: pgsql-students@postgresql.org
Hello,
My name is Camelia, I carry out Doctoral/PhD research in the field of database query processing and I'd like to contribute with PostgreSQL optimization tasks during this year's GSoC:
- Optimization- add to the join removal code the ability to remove joins to tables when the join is on a foreign key column (where all entries must exist in the parent anyway)
- Optimization- Check the set of conditionals on a WHERE clause against CHECK constraints on the table being queried and remove any conditionals which *must* be true due to the CHECK constraints
and others that may appear interesting along my review of the source code.
I'm very excited about this opportunity and I hope that the results will be as good!
Will the aforementioned subjects be open for work or do other committers have them under work already?
Do you have a specific template for the project proposal?
Thank you very much!
Best regards,
CameliaHi Camelia! Thanks for your interest in PostgreSQL! * Camelia C (camelia13c@gmail.com) wrote: > My name is Camelia, I carry out Doctoral/PhD research in the field of > database query processing and I'd like to contribute with PostgreSQL > optimization tasks during this year's GSoC: > > - Optimization- add to the join removal code the ability to remove joins > to tables when the join is on a foreign key column (where all entries must > exist in the parent anyway) There has actually been quite a bit of discussion about exactly that, along with various patches proposed. This work has been lead by David Rowley and the discussion can be found here: http://www.postgresql.org/message-id/flat/CAApHDvocUEYdt1uT+DLDPs2xEu=v3qJGT6HeXKonQM4rY_OsSA@mail.gmail.com#CAApHDvocUEYdt1uT+DLDPs2xEu=v3qJGT6HeXKonQM4rY_OsSA@mail.gmail.com > - Optimization- Check the set of conditionals on a WHERE clause against > CHECK constraints on the table being queried and remove any conditionals > which *must* be true due to the CHECK constraints This is an interesting optimization that I don't believe anyone is currently working on. We do look at WHERE clauses and compare them against the CHECK constraints for the purposes of working out if the WHERE clause could ever possibly be true (and, if it can't, then we omit that table from consideration for the query), but I don't believe we go the other direction and remove the conditional check when the CHECK shows that the conditional must always be *true*. I'd be very interested in understanding where that particular optimization is relevant (and that will be an important factor which will be considered when deciding if this is a worthwhile effort). > and others that may appear interesting along my review of the source code. I'd certainly be happy to discuss any other thoughts you have along these lines. Note that while we are always interested in improvements to our optimizer, we are also concerned with the length of time that it takes for the optimizer to decide upon a plan. We won't include optimizations which have a high run-time cost unless there is a high probability that they result in a query execution run-time which is much better. > I'm very excited about this opportunity and I hope that the results will be > as good! It's great to see your interest in the optimizer! > Will the aforementioned subjects be open for work or do other committers > have them under work already? Per above, the first is actively being worked on, but not the second. > Do you have a specific template for the project proposal? I don't believe we do. Hopefully Thom or one of the other admins will correct me if I got that wrong. :) Thanks! Stephen
Вложения
Camelia, While that provides a guideline for what you'll want to include in your proposal, I believe you have some amount of freedom both in how much you cover each of those topic areas and the ordering of them. You are also welcome to include any other information which is relevant and supports your proposal. Thanks! Stephen * Camelia C (camelia13c@gmail.com) wrote: > Hello, > > For my second question, I guess that [1] provides the information of the > expected parts of the project proposal. > > However, I expect some feedback from your part about the topic chosen > before I jump into writing the project proposal. > > Thanks! > > Have a nice week-end, > Camelia > > [1] http://www.postgresql.org/developer/summerofcode/#proposals > > > ---------- Forwarded message ---------- > From: Camelia C <camelia13c@gmail.com> > Date: Thu, Mar 5, 2015 at 3:54 AM > Subject: [GSoC] Optimization tasks > To: pgsql-students@postgresql.org > > > Hello, > > My name is Camelia, I carry out Doctoral/PhD research in the field of > database query processing and I'd like to contribute with PostgreSQL > optimization tasks during this year's GSoC: > > - Optimization- add to the join removal code the ability to remove joins > to tables when the join is on a foreign key column (where all entries must > exist in the parent anyway) > - Optimization- Check the set of conditionals on a WHERE clause against > CHECK constraints on the table being queried and remove any conditionals > which *must* be true due to the CHECK constraints > > and others that may appear interesting along my review of the source code. > > I'm very excited about this opportunity and I hope that the results will be > as good! > > Will the aforementioned subjects be open for work or do other committers > have them under work already? > Do you have a specific template for the project proposal? > > Thank you very much! > > Best regards, > Camelia