Thread

1. Need a mentor, and a project.

   Ashish <abindra@u.washington.edu> — 2009-12-07T02:24:55Z

   Hello there,
   
   I am a graduate student at the University of Washington, Tacoma
   (http://www.tacoma.washington.edu/tech/) with an interest in databases (especially query processing). I am familiar with database theory and in an earlier life I used to be an application developer and have done a lot of SQL/database related work. I have been interested in learning and contribution to postgres for a while now. This quarter I was the TA for the undergrad intro to database class. I convinced my Prof. to use Postgresql to teach and it has been fun. It has also allowed me to familiarize myself with postgres from an external user's point of view.
   
   Next quarter I am planning to do an Independent Study course where the main objective would be to allow me to get familiar with the internals of Postgres by working on a project(s). I would like to work on something that could possibly be accepted as a patch.
   
   This is (I think) somewhat similar to what students do during google summer and I was hoping to get some help here in terms of:
   1. A good project to work on for a newbie.
   2. Would someone be willing to be a mentor? It would be nice to be able to get some guidance on a one-to-one basis.
   
   Thanks for your time. If you have any questions or need more information, please do let me know.
   
   Regards
   Ashish
   
   
   
   
   
   
   
   

2. Re: Need a mentor, and a project.

   Albe Laurenz <laurenz.albe@wien.gv.at> — 2009-12-07T08:53:32Z

   abindra wrote:
   > Next quarter I am planning to do an Independent Study course 
   > where the main objective would be to allow me to get familiar 
   > with the internals of Postgres by working on a project(s). I 
   > would like to work on something that could possibly be 
   > accepted as a patch.
   > 
   > This is (I think) somewhat similar to what students do during 
   > google summer and I was hoping to get some help here in terms of:
   > 1. A good project to work on for a newbie.
   > 2. Would someone be willing to be a mentor? It would be nice 
   > to be able to get some guidance on a one-to-one basis.
   
   I would start with the TODO list: http://wiki.postgresql.org/wiki/Todo
   These are things for which there is a consensus that it would be
   a good idea to implement them. Pick things that look interesting to
   you, and try to read the discussions in the archives that lead
   to the TODO items.
   
   Bring the topic up in the hackers list, say that you would like
   to work on this or that TODO item, present your ideas of how you
   want to do it. Ask about things where you feel insecure.
   If you get some support, proceed to write a patch. Ask for
   directions, post half-baked patches and ask for comments.
   
   That is because you will probably receive a good amount of
   critizism and maybe rejection, and if you invest a couple of
   months into working on something that nobody knows about *and*
   your work gets rejected, that is much worse than drawing fire
   right away.
   
   It's probably not easy to find a mentor (unless you have money
   to give away), but you may find people who are interested in
   what you are doing and who will help you.
   
   Yours,
   Laurenz Albe
   
   

3. Re: Need a mentor, and a project.

   Joshua Tolley <eggyknap@gmail.com> — 2009-12-07T15:18:18Z

   On Mon, Dec 07, 2009 at 09:53:32AM +0100, Albe Laurenz wrote:
   > abindra wrote:
   > > Next quarter I am planning to do an Independent Study course 
   > > where the main objective would be to allow me to get familiar 
   > > with the internals of Postgres by working on a project(s). I 
   > > would like to work on something that could possibly be 
   > > accepted as a patch.
   > > 
   > > This is (I think) somewhat similar to what students do during 
   > > google summer and I was hoping to get some help here in terms of:
   > > 1. A good project to work on for a newbie.
   > > 2. Would someone be willing to be a mentor? It would be nice 
   > > to be able to get some guidance on a one-to-one basis.
   > 
   > I would start with the TODO list: http://wiki.postgresql.org/wiki/Todo
   > These are things for which there is a consensus that it would be
   > a good idea to implement them. Pick things that look interesting to
   > you, and try to read the discussions in the archives that lead
   > to the TODO items.
   
   I agree the TODO list is a good place to start. Other good sources include the
   -hackers list and comments in the code. I was surprised when I began taking an
   interest in PostgreSQL how rarely interesting projects mentioned on -hackers
   made it into the TODO list; I've come to realize that the TODO contains, in
   general, very non-controversial items everyone is pretty sure we could use,
   whereas -hackers ranges freely over other topics which are still very
   interesting but often more controversial or less obviously necessary.
   Committed patches both large and small address TODO list items fairly rarely,
   so don't get too hung up on finding something from the TODO list alone.
   
   > Bring the topic up in the hackers list, say that you would like
   > to work on this or that TODO item, present your ideas of how you
   > want to do it. Ask about things where you feel insecure.
   > If you get some support, proceed to write a patch. Ask for
   > directions, post half-baked patches and ask for comments.
   > 
   > That is because you will probably receive a good amount of
   > critizism and maybe rejection, and if you invest a couple of
   > months into working on something that nobody knows about *and*
   > your work gets rejected, that is much worse than drawing fire
   > right away.
   
   +1. Especially when developing a complex patch, and especially when you're new
   to the community, you need to avoid working in a vacuum, for social as well as
   technical reasons. The more complex a patch, the more consensus you'll
   eventually need to achieve before getting it committed, in general, and it
   helps to gain that consensus early on, rather than after you've written a lot
   of code. The keyword "proposal" might be a useful search term when digging in
   the -hackers archives for historical examples.
   
   --
   Joshua Tolley / eggyknap
   End Point Corporation
   http://www.endpoint.com
   

4. Re: Need a mentor, and a project.

   Robert Haas <robertmhaas@gmail.com> — 2009-12-07T16:05:05Z

   On Sun, Dec 6, 2009 at 9:24 PM,  <abindra@u.washington.edu> wrote:
   > 2. Would someone be willing to be a mentor? It would be nice to be able to get some guidance on a one-to-one basis.
   
   I might be willing to do this, but if you pick a project that is
   outside my area of knowledge then I might not be able to help as much.
   
   ...Robert
   
   

5. Re: Need a mentor, and a project.

   Ashish <abindra@u.washington.edu> — 2009-12-08T00:41:22Z

   Albe & Joshua, thanks for the advice. I am in the process of deciding what to work on and am looking at the TODO list. I definitely do not intend to work in a vacuum :-) I am really excited about this and look forward to being challenged and learning a lot.
   
   Regards
   Ashish
   
   
   On Mon, 7 Dec 2009, Joshua Tolley wrote:
   
   > On Mon, Dec 07, 2009 at 09:53:32AM +0100, Albe Laurenz wrote:
   >> abindra wrote:
   >>> Next quarter I am planning to do an Independent Study course
   >>> where the main objective would be to allow me to get familiar
   >>> with the internals of Postgres by working on a project(s). I
   >>> would like to work on something that could possibly be
   >>> accepted as a patch.
   >>>
   >>> This is (I think) somewhat similar to what students do during
   >>> google summer and I was hoping to get some help here in terms of:
   >>> 1. A good project to work on for a newbie.
   >>> 2. Would someone be willing to be a mentor? It would be nice
   >>> to be able to get some guidance on a one-to-one basis.
   >>
   >> I would start with the TODO list: http://wiki.postgresql.org/wiki/Todo
   >> These are things for which there is a consensus that it would be
   >> a good idea to implement them. Pick things that look interesting to
   >> you, and try to read the discussions in the archives that lead
   >> to the TODO items.
   >
   > I agree the TODO list is a good place to start. Other good sources include the
   > -hackers list and comments in the code. I was surprised when I began taking an
   > interest in PostgreSQL how rarely interesting projects mentioned on -hackers
   > made it into the TODO list; I've come to realize that the TODO contains, in
   > general, very non-controversial items everyone is pretty sure we could use,
   > whereas -hackers ranges freely over other topics which are still very
   > interesting but often more controversial or less obviously necessary.
   > Committed patches both large and small address TODO list items fairly rarely,
   > so don't get too hung up on finding something from the TODO list alone.
   >
   >> Bring the topic up in the hackers list, say that you would like
   >> to work on this or that TODO item, present your ideas of how you
   >> want to do it. Ask about things where you feel insecure.
   >> If you get some support, proceed to write a patch. Ask for
   >> directions, post half-baked patches and ask for comments.
   >>
   >> That is because you will probably receive a good amount of
   >> critizism and maybe rejection, and if you invest a couple of
   >> months into working on something that nobody knows about *and*
   >> your work gets rejected, that is much worse than drawing fire
   >> right away.
   >
   > +1. Especially when developing a complex patch, and especially when you're new
   > to the community, you need to avoid working in a vacuum, for social as well as
   > technical reasons. The more complex a patch, the more consensus you'll
   > eventually need to achieve before getting it committed, in general, and it
   > helps to gain that consensus early on, rather than after you've written a lot
   > of code. The keyword "proposal" might be a useful search term when digging in
   > the -hackers archives for historical examples.
   >
   > --
   > Joshua Tolley / eggyknap
   > End Point Corporation
   > http://www.endpoint.com
   >
   
   
   
   

6. Re: Need a mentor, and a project.

   Josh Berkus <josh@agliodbs.com> — 2009-12-08T00:46:03Z

   On 12/7/09 4:41 PM, Ashish wrote:
   > Albe & Joshua, thanks for the advice. I am in the process of deciding
   > what to work on and am looking at the TODO list. I definitely do not
   > intend to work in a vacuum :-) I am really excited about this and look
   > forward to being challenged and learning a lot.
   
   When you decide what you want to work on, let us know and we'll try to
   find you an appropriate mentor.
   
   --Josh Berkus
   
   

7. Re: Need a mentor, and a project.

   Ashish <abindra@u.washington.edu> — 2009-12-08T01:04:58Z

   Hi Robert,
   
   Thanks. If I may, what encompasses your area of expertise...
   
   BTW Congratulation on becoming a committer!
   
   Regards
   Ashish
   
   On Mon, 7 Dec 2009, Robert Haas wrote:
   
   > On Sun, Dec 6, 2009 at 9:24 PM,  <abindra@u.washington.edu> wrote:
   >> 2. Would someone be willing to be a mentor? It would be nice to be able to get some guidance on a one-to-one basis.
   >
   > I might be willing to do this, but if you pick a project that is
   > outside my area of knowledge then I might not be able to help as much.
   >
   > ...Robert
   >
   
   
   
   

8. Re: Need a mentor, and a project.

   Robert Haas <robertmhaas@gmail.com> — 2009-12-08T03:22:25Z

   On Mon, Dec 7, 2009 at 8:04 PM, Ashish <abindra@u.washington.edu> wrote:
   > Hi Robert,
   >
   > Thanks. If I may, what encompasses your area of expertise...
   >
   > BTW Congratulation on becoming a committer!
   
   Thanks.  As others have said, it's probably best to pick a project
   first, or at least an area.  It's more important to find something
   you're interested in working on than to think about working with some
   particular person.
   
   ...Robert
   
   

9. Re: Need a mentor, and a project.

   Peter Eisentraut <peter_e@gmx.net> — 2009-12-09T18:00:22Z

   On mån, 2009-12-07 at 09:53 +0100, Albe Laurenz wrote:
   > I would start with the TODO list: http://wiki.postgresql.org/wiki/Todo
   > These are things for which there is a consensus that it would be
   > a good idea to implement them.
   
   The Todo list is not a list of things for which such a consensus exists.
   The Todo list is in general a list of things that someone thought should
   be considered at some point.  But unless the item is linked to a mailing
   list thread that already shows a consensus about the feature, you need
   to start with a discussion about a plan.
   
   So don't submit a project plan to your university or boss based on "I
   will work on item X because it's on the Todo list" without taking ample
   time to discuss things here first.
   
   
   

10. Re: Need a mentor, and a project.

    Greg Smith <greg@2ndquadrant.com> — 2009-12-09T18:25:46Z

    Peter Eisentraut wrote:
    > But unless the item is linked to a mailing
    > list thread that already shows a consensus about the feature, you need
    > to start with a discussion about a plan.
    >   
    And realistically, even if the item is so linked, someone new to the 
    project still shouldn't just plow away on it without asking for 
    confirmation first anyway.  There are many things on the TODO list that 
    everyone would like to see fixed, the problem is well defined and 
    unambiguous, but the way the solution needs to be structured is much 
    harder than is obvious.  As a simplest example, we regularly have people 
    show up with patches where the "solution" was "just add threading to the 
    back-end here..." which might seem completely reasonable to someone 
    new--but it will never get committed.
    
    -- 
    Greg Smith    2ndQuadrant   Baltimore, MD
    PostgreSQL Training, Services and Support
    greg@2ndQuadrant.com  www.2ndQuadrant.com
    
    
    

11. Re: Need a mentor, and a project.

    Ashish <abindra@u.washington.edu> — 2009-12-12T02:00:53Z

    I am thinking about starting with the following TODO item:
    
    --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated and actual row counts differ by a specified percentage.
    
    I picked this because it is somewhat related to query processing which is what I am most interested in. It also <seems> like a good start up project for a newbie like me. Before I start looking into what this would involve and start a conversation on designing a solution - I wanted to know what you guys think about this particular TODO, and it suitability to a newbie. Looking forward to your comments...
    
    Thanks
    Ashish
    
    On Mon, 7 Dec 2009, Josh Berkus wrote:
    
    > On 12/7/09 4:41 PM, Ashish wrote:
    >> Albe & Joshua, thanks for the advice. I am in the process of deciding
    >> what to work on and am looking at the TODO list. I definitely do not
    >> intend to work in a vacuum :-) I am really excited about this and look
    >> forward to being challenged and learning a lot.
    >
    > When you decide what you want to work on, let us know and we'll try to
    > find you an appropriate mentor.
    >
    > --Josh Berkus
    >
    
    
    
    

12. Re: Need a mentor, and a project.

    Bruce Momjian <bruce@momjian.us> — 2009-12-12T02:05:02Z

    Ashish wrote:
    > I am thinking about starting with the following TODO item:
    > 
    > --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    > and actual row counts differ by a specified percentage.
    > 
    > I picked this because it is somewhat related to query processing
    > which is what I am most interested in. It also <seems> like a
    > good start up project for a newbie like me. Before I start
    > looking into what this would involve and start a conversation
    > on designing a solution - I wanted to know what you guys think
    > about this particular TODO, and it suitability to a newbie.
    > Looking forward to your comments...
    
    I even have a sample patch you can use as a start, attached.
    
    --
      Bruce Momjian  <bruce@momjian.us>        http://momjian.us
      EnterpriseDB                             http://enterprisedb.com
    
      + If your life is a hard drive, Christ can be your backup. +
    

13. Re: Need a mentor, and a project.

    Robert Haas <robertmhaas@gmail.com> — 2009-12-12T02:28:28Z

    On Fri, Dec 11, 2009 at 9:00 PM, Ashish <abindra@u.washington.edu> wrote:
    > I am thinking about starting with the following TODO item:
    >
    > --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated and actual
    > row counts differ by a specified percentage.
    >
    > I picked this because it is somewhat related to query processing which is
    > what I am most interested in. It also <seems> like a good start up project
    > for a newbie like me. Before I start looking into what this would involve
    > and start a conversation on designing a solution - I wanted to know what you
    > guys think about this particular TODO, and it suitability to a newbie.
    > Looking forward to your comments...
    
    If we're going to do this, I think we should implement this as an
    optional behavior controlled by a new EXPLAIN option (maybe VARIANCE,
    following Bruce's patch?) and generate the output using
    ExplainProperty<some-data-type>.  We could possibly make the option
    take an optional threshold indicating how much variance is required
    before the variance gets displayed, and display the variance for every
    node if VARIANCE is specified without an argument.
    
    ...Robert
    
    

14. Re: Need a mentor, and a project.

    Robert Haas <robertmhaas@gmail.com> — 2009-12-12T02:30:20Z

    On Fri, Dec 11, 2009 at 9:05 PM, Bruce Momjian <bruce@momjian.us> wrote:
    > Ashish wrote:
    >> I am thinking about starting with the following TODO item:
    >>
    >> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    >> and actual row counts differ by a specified percentage.
    >>
    >> I picked this because it is somewhat related to query processing
    >> which is what I am most interested in. It also <seems> like a
    >> good start up project for a newbie like me. Before I start
    >> looking into what this would involve and start a conversation
    >> on designing a solution - I wanted to know what you guys think
    >> about this particular TODO, and it suitability to a newbie.
    >> Looking forward to your comments...
    >
    > I even have a sample patch you can use as a start, attached.
    
    Interesting.  The logic in ExplainVariance() doesn't look right to me
    - the cases where one argument is zero seem like they will produce a
    differently-scaled result than otherwise.
    
    ...Robert
    
    

15. Re: Need a mentor, and a project.

    Bruce Momjian <bruce@momjian.us> — 2009-12-12T02:36:55Z

    Robert Haas wrote:
    > On Fri, Dec 11, 2009 at 9:05 PM, Bruce Momjian <bruce@momjian.us> wrote:
    > > Ashish wrote:
    > >> I am thinking about starting with the following TODO item:
    > >>
    > >> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    > >> and actual row counts differ by a specified percentage.
    > >>
    > >> I picked this because it is somewhat related to query processing
    > >> which is what I am most interested in. It also <seems> like a
    > >> good start up project for a newbie like me. Before I start
    > >> looking into what this would involve and start a conversation
    > >> on designing a solution - I wanted to know what you guys think
    > >> about this particular TODO, and it suitability to a newbie.
    > >> Looking forward to your comments...
    > >
    > > I even have a sample patch you can use as a start, attached.
    > 
    > Interesting.  The logic in ExplainVariance() doesn't look right to me
    > - the cases where one argument is zero seem like they will produce a
    > differently-scaled result than otherwise.
    
    Yea, it is just a starting point for him.
    
    -- 
      Bruce Momjian  <bruce@momjian.us>        http://momjian.us
      EnterpriseDB                             http://enterprisedb.com
    
      + If your life is a hard drive, Christ can be your backup. +
    
    

16. Re: Need a mentor, and a project.

    Tom Lane <tgl@sss.pgh.pa.us> — 2009-12-12T02:44:42Z

    Bruce Momjian <bruce@momjian.us> writes:
    > Ashish wrote:
    >> I am thinking about starting with the following TODO item:
    >> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    >> and actual row counts differ by a specified percentage.
    
    > I even have a sample patch you can use as a start, attached.
    
    Of course, the reason that patch isn't already in there is that it's
    pretty much useless.  It clutters what's already cluttered output
    and doesn't do much of anything to help draw one's attention to the
    larger estimation errors, which of course is what the TODO item is
    really about.
    
    IMO the hard part of the TODO item is to design a useful user interface
    for highlighting specific EXPLAIN entries (and NOTICE messages probably
    ain't it either).  Getting the numbers is trivial.
    
    I'm not sure there is any really nice solution within the confines of
    plain ASCII text output.  There was an interesting approach online
    at http://explain-analyze.info, but that site seems to be down now :-(
    
    			regards, tom lane
    
    

17. Re: Need a mentor, and a project.

    Euler Taveira <euler@timbira.com> — 2009-12-12T04:01:04Z

    Tom Lane escreveu:
    > I'm not sure there is any really nice solution within the confines of
    > plain ASCII text output.  There was an interesting approach online
    > at http://explain-analyze.info, but that site seems to be down now :-(
    > 
    Estimation error is one of the ideas. The other ones I have in mind is: (i)
    accumulative time or percentage per node and (ii) color node that has
    estimation off (if the terminal support colors). Of course, those features
    should be enabled using some explain options like ACCUMULATIVE and COLOR.
    
    Another explain tool that has a similar approach is http://explain.depesz.com/ .
    
    
    -- 
      Euler Taveira de Oliveira
      http://www.timbira.com/
    
    

18. Re: Need a mentor, and a project.

    Decibel! <decibel@decibel.org> — 2009-12-15T20:31:19Z

    On Dec 11, 2009, at 8:44 PM, Tom Lane wrote:
    > Bruce Momjian <bruce@momjian.us> writes:
    >> Ashish wrote:
    >>> I am thinking about starting with the following TODO item:
    >>> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    >>> and actual row counts differ by a specified percentage.
    > 
    >> I even have a sample patch you can use as a start, attached.
    > 
    > IMO the hard part of the TODO item is to design a useful user interface
    > for highlighting specific EXPLAIN entries (and NOTICE messages probably
    > ain't it either).  Getting the numbers is trivial.
    
    What about prefixing explain output with line numbers? NOTICEs (or whatever mechanism) could then reference the line numbers.
    
    Unfortunately, I think you'll be very hard-pressed to come up with a way to denote problems on the lines themselves, since horizontal space is already very hard to come by in complex plans.
    --
    Jim C. Nasby, Database Architect                   jim@nasby.net
    512.569.9461 (cell)                         http://jim.nasby.net
    
    
    
    

19. Re: Need a mentor, and a project.

    Gurjeet Singh <singh.gurjeet@gmail.com> — 2009-12-16T08:14:41Z

    2009/12/16 decibel <decibel@decibel.org>
    
    > On Dec 11, 2009, at 8:44 PM, Tom Lane wrote:
    > > Bruce Momjian <bruce@momjian.us> writes:
    > >> Ashish wrote:
    > >>> I am thinking about starting with the following TODO item:
    > >>> --> Have EXPLAIN ANALYZE issue NOTICE messages when the estimated
    > >>> and actual row counts differ by a specified percentage.
    > >
    > >> I even have a sample patch you can use as a start, attached.
    > >
    > > IMO the hard part of the TODO item is to design a useful user interface
    > > for highlighting specific EXPLAIN entries (and NOTICE messages probably
    > > ain't it either).  Getting the numbers is trivial.
    >
    > What about prefixing explain output with line numbers? NOTICEs (or whatever
    > mechanism) could then reference the line numbers.
    >
    >
    +1
    
    -- 
    Lets call it Postgres
    
    EnterpriseDB      http://www.enterprisedb.com
    
    gurjeet[.singh]@EnterpriseDB.com
    
    singh.gurjeet@{ gmail | hotmail | indiatimes | yahoo }.com
    Twitter: singh_gurjeet
    Skype: singh_gurjeet
    
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