Re: GSOC PostgreSQL partitioning issue

On Fri, Apr 9, 2010 at 9:10 AM, Necati Batur <necatibatur(at)gmail(dot)com> wrote:
> I am new at open source project however in a user point of view I must
> confess that usability is a really though issue ,even if the performance of
> a database is crucial.

Sure. Nobody is saying otherwise.

> As to my idea for improve postgresql is ;
> http://www.postgresql.org/docs/current/interactive/ddl-partitioning.html  in
> cavetaes section is mentioned that
> "The schemes shown here assume that the partition key column(s) of a row
> never change, or at least do not change enough to require it to move to
> another partition. An UPDATE that attempts to do that will fail because of
> the CHECK constraints. If you need to handle such cases, you can put
> suitable update triggers on the partition tables, but it makes management of
> the structure much more complicated."
> Fixing this issue will help to improve the usability of partitions since the
> users do not want to deal with low-level integrity issues such as CHECK
> constraint.
> Roughly, I can say that if we want to deal with this issue,the first
> operation would be writing a trigger to check if an update operation causes
> a transfer issue between partitions.Then, if it is inevitable the user
> should be prompted about they are doing. Warning the system or user would
> generallry causes more trouble this point we need to decide on possible
> fixing ways and give more details about which choise will cause in what
> results. Then, creating a temprory table before commiting something will
> hellp us to conrol completeness and correctness.
> I tried to give more details about what I want to do.If you anything should
> be fixed in my proposal please earn me.

This issue is, as Greg says, far more complicated than you realize. I
would like to recommend again, as I did previously off-list, that you
pick an easier project. Here again is the link to some ideas I wrote
up previously.

http://archives.postgresql.org/pgsql-hackers/2010-03/msg01034.php

If you insist on pursuing a problem that you don't really understand
and that is far larger than what you can tackle in one summer, then
you are not going to be successful.

...Robert