Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-04-09 Thread Bruce Momjian
On Tue, Mar 20, 2012 at 01:25:15PM +0100, Claes Jakobsson wrote:
 
 On 20 mar 2012, at 13.08, Heikki Linnakangas wrote:
  On 20.03.2012 11:10, Claes Jakobsson wrote:
  
  Personally I'd love a type 2 JDBC driver for PostgreSQL.
  
  Why?
 
 listen/notify over SSL for example unless that's been fixed in the
 JDBC driver recently. And I'm sure there are other things in libpq that
 would be nice to have.As mainly a Perl dude which uses libpq via
 DBD::Pg I find it odd that the Java people doesn't do the same instead
 of reimplementing everything.

Well, I assume they reimplemented libpq so that java would not rely on a
platform-specific library like libpq.

-- 
  Bruce Momjian  br...@momjian.ushttp://momjian.us
  EnterpriseDB http://enterprisedb.com

  + It's impossible for everything to be true. +

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-04-09 Thread Merlin Moncure
On Mon, Apr 9, 2012 at 1:14 PM, Bruce Momjian br...@momjian.us wrote:
 Well, I assume they reimplemented libpq so that java would not rely on a
 platform-specific library like libpq.

yes, that is correct.  jdbc for postgres is a complete implementation
of the client side protocol.  this has some good and bad points -- on
the good side you have some features libpq is only about to get, like
row level result processing, but on them minus side you are missing
some features libpq has, like gssapi authentication (but you can still
get that with jdbc-odbc bridge).

but generally speaking jdbc is displacing odbc as the 'go to' library
for connection between different kinds of database systems, especially
on non-windows environments.  jdbc is to java as fdw is to postgres
basically.  so a fdw exposed jdbc driver should be able to connect and
gather data from just about anything -- even something like sql server
so that you could bypass the freetds dependency which is quite nice.

there's an odbc-fdw project that does something pretty similar and
might be a more natural choice for windows coders.

merlin

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-04-09 Thread Andrew Dunstan



On 04/09/2012 02:14 PM, Bruce Momjian wrote:

On Tue, Mar 20, 2012 at 01:25:15PM +0100, Claes Jakobsson wrote:

On 20 mar 2012, at 13.08, Heikki Linnakangas wrote:

On 20.03.2012 11:10, Claes Jakobsson wrote:

Personally I'd love a type 2 JDBC driver for PostgreSQL.

Why?

listen/notify over SSL for example unless that's been fixed in the
JDBC driver recently. And I'm sure there are other things in libpq that
would be nice to have.As mainly a Perl dude which uses libpq via
DBD::Pg I find it odd that the Java people doesn't do the same instead
of reimplementing everything.

Well, I assume they reimplemented libpq so that java would not rely on a
platform-specific library like libpq.



Type 4 drivers are the norm in the Java world. You would find it much 
more difficult to get traction among Java users, in my experience, with 
a driver that's not pure Java.


And in any case, I think it's a good thing to have two significant 
independent implementations of the wire protocol out there.


Note too that the maintainer of the Perl DBD driver has opined in my 
hearing that he would like to be able to move from relying on libpq to 
having a pure Perl driver (although personally speaking I'm glad he hasn't.)



cheers

andrew

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-04-09 Thread Bruce Momjian
On Mon, Apr 09, 2012 at 01:29:46PM -0500, Merlin Moncure wrote:
 but generally speaking jdbc is displacing odbc as the 'go to' library
 for connection between different kinds of database systems, especially
 on non-windows environments.  jdbc is to java as fdw is to postgres
 basically.  so a fdw exposed jdbc driver should be able to connect and
 gather data from just about anything -- even something like sql server
 so that you could bypass the freetds dependency which is quite nice.

Yes, I can see jdbc-fdw being very powerful.

-- 
  Bruce Momjian  br...@momjian.ushttp://momjian.us
  EnterpriseDB http://enterprisedb.com

  + It's impossible for everything to be true. +

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-25 Thread Claes Jakobsson
On 19 mar 2012, at 22.45, Merlin Moncure wrote:
 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

Personally I'd love a type 2 JDBC driver for PostgreSQL. It should be feasible 
as a summer project. It's somewhere deep down on my TODO list so I'd be happy 
to help.

Cheers,
Claes 
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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-25 Thread Claes Jakobsson

On 20 mar 2012, at 13.08, Heikki Linnakangas wrote:
 On 20.03.2012 11:10, Claes Jakobsson wrote:
 
 Personally I'd love a type 2 JDBC driver for PostgreSQL.
 
 Why?

listen/notify over SSL for example unless that's been fixed in the JDBC driver 
recently. And I'm sure there are other things in libpq that would be nice to 
have.

As mainly a Perl dude which uses libpq via DBD::Pg I find it odd that the Java 
people doesn't do the same instead of reimplementing everything.

Cheers,
/Claes


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-23 Thread Merlin Moncure
On Wed, Mar 21, 2012 at 10:51 PM, Atri Sharma atri.j...@gmail.com wrote:
 Please let me know how to proceed further.

 Waiting for your reply,

sure -- let's take this discussion off line.  send me a private mail
and we'll discuss if/how we can get this off the ground.

merlin

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-21 Thread Atri Sharma


-Original Message-
From: Atri Sharma [mailto:atri.j...@gmail.com] 
Sent: 22 March 2012 09:20
To: 'Atri Sharma'
Subject: RE: [HACKERS] Regarding column reordering project for GSoc 2012



-Original Message-
From: Atri Sharma [mailto:atri.j...@gmail.com] 
Sent: 20 March 2012 23:05
To: 'Merlin Moncure'
Cc: 'Heikki Linnakangas'; 'Alvaro Herrera'; 'Daniel Farina'; 'Andrew
Dunstan'; 'Dave Page'; 'Pg Hackers'
Subject: RE: [HACKERS] Regarding column reordering project for GSoc 2012



-Original Message-
From: Merlin Moncure [mailto:mmonc...@gmail.com] 
Sent: 20 March 2012 22:50
To: Atri Sharma
Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
Page; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Tue, Mar 20, 2012 at 11:57 AM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 20:52
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan;
Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave
Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

 sure:
 first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
 and take a look at all the various fdw projects.  they all utilize the
 high level interfaces that postgresql provides to incorporate external
 datasources and expose them you can query them as if they were views
 or tables.  as you can see, this interface is popular with the
 proliferation of projects to expose this or that.  what i'm thinking
 is you make a fdw that invokes pl/java routines that make jdbc calls
 out to external databases.  for fetching data and building sets.  as
 long as you stick to vanilla jdbc calls, you then have a fdw that can
 gather data from pretty much anything you can access via jdbc url
 which is quite nice.

 The fdw API is a C api, so you need to figure out how to proxy to your
 pl/java calls where the real work is done -- I  haven't done that so
I'm not sure if this is even technically feasible.  If you can make
 SPI calls from your fdw routines, that's one path through.   Tou have
 lots of previous work to crib from though and hopefully there's a path
 through.  As far as the ETL stuff I was talking about -- that was just
 me thinking out loud...better to just get the basic mechanics working
 up front..  For now, if you're interested in doing this, start
 thinking about how to marry the fdw interface to pl/java...one you get
 'hello world' there, it's all about where you want tot take it.

 This is an interesting project -- you should entertain no illusions of
 it making it into core, but if done right and completed it will raise
 visibility of both pl/java and postgresql.

 Merlin


 
-
Hi Merlin,

Please let me know how

Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma


-Original Message-
From: Claes Jakobsson [mailto:cl...@versed.se] 
Sent: 20 March 2012 14:40
To: Merlin Moncure
Cc: Heikki Linnakangas; Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew
Dunstan; Dave Page; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On 19 mar 2012, at 22.45, Merlin Moncure wrote:
 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

Personally I'd love a type 2 JDBC driver for PostgreSQL. It should be
feasible as a summer project. It's somewhere deep down on my TODO list so
I'd be happy to help.

Cheers,
Claes 


--
Hi Claes,

Thank you for taking time to reply to my query.

I would simply love to implement a type 2 JDBC driver.It would be simply
wonderful to add this feature to PL/Java (IMHO).

Please let me know how to proceed further.Also,I would request you to please
mentor me in this pet project of yours.

Thanks a lot for giving me this project idea.

Waiting for your reply,

Atri


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma
-Original Message-
From: Merlin Moncure [mailto:mmonc...@gmail.com] 
Sent: 20 March 2012 03:15
To: Heikki Linnakangas
Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave Page;
Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
The
 last release was in September 2011, and there are active discussions on
the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

pl/java works pretty well and is somewhat widely used although it
might need some more active maintainers.  just jumping into the
project and nailing some old bugs and getting the juices flowing would
be a tremendous help, as well as the less glamorous work of
documentation and regular status updates.

one pl/java based project that IMO is just screaming to be done is a
pl/java based FDW (wrapping JDBC) that would approximately reproduce
dblink...maybe with some extra features geared towards ETL type jobs
like a row based callback for transformations in java.

Merlin


---
Hi Merlin

Thanks for the idea.

Could you please elaborate more on the project idea? It would be a great
help for me.

Atri


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Heikki Linnakangas

On 20.03.2012 11:10, Claes Jakobsson wrote:

On 19 mar 2012, at 22.45, Merlin Moncure wrote:

one pl/java based project that IMO is just screaming to be done is a
pl/java based FDW (wrapping JDBC) that would approximately reproduce
dblink...maybe with some extra features geared towards ETL type jobs
like a row based callback for transformations in java.


Personally I'd love a type 2 JDBC driver for PostgreSQL.


Why?

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma
-Original Message-
From: Heikki Linnakangas [mailto:heikki.linnakan...@enterprisedb.com] 
Sent: 20 March 2012 17:39
To: Claes Jakobsson
Cc: Merlin Moncure; Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew
Dunstan; Dave Page; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On 20.03.2012 11:10, Claes Jakobsson wrote:
 On 19 mar 2012, at 22.45, Merlin Moncure wrote:
 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Personally I'd love a type 2 JDBC driver for PostgreSQL.

Why?

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com


---

Hi Heikki,

one pl/java based project that IMO is just screaming to be done is a
pl/java based FDW (wrapping JDBC) that would approximately reproduce
dblink...maybe with some extra features geared towards ETL type jobs
like a row based callback for transformations in java.

The project will be wrapping JDBC in a wrapper class and adding ETL
features?

Please elaborate a bit more.I am not too sure if I understand it completely.

Waiting for your reply,

Atri



Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Merlin Moncure
On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

sure:
first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
and take a look at all the various fdw projects.  they all utilize the
high level interfaces that postgresql provides to incorporate external
datasources and expose them you can query them as if they were views
or tables.  as you can see, this interface is popular with the
proliferation of projects to expose this or that.  what i'm thinking
is you make a fdw that invokes pl/java routines that make jdbc calls
out to external databases.  for fetching data and building sets.  as
long as you stick to vanilla jdbc calls, you then have a fdw that can
gather data from pretty much anything you can access via jdbc url
which is quite nice.

The fdw API is a C api, so you need to figure out how to proxy to your
pl/java calls where the real work is done -- I  haven't done that so
I'm not sure if this is even technically feasible.  If you can make
SPI calls from your fdw routines, that's one path through.   Tou have
lots of previous work to crib from though and hopefully there's a path
through.  As far as the ETL stuff I was talking about -- that was just
me thinking out loud...better to just get the basic mechanics working
up front..  For now, if you're interested in doing this, start
thinking about how to marry the fdw interface to pl/java...one you get
'hello world' there, it's all about where you want tot take it.

This is an interesting project -- you should entertain no illusions of
it making it into core, but if done right and completed it will raise
visibility of both pl/java and postgresql.

merlin

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Jeff Janes
On Mon, Mar 19, 2012 at 12:29 PM, Alvaro Herrera
alvhe...@commandprompt.com wrote:

 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.

 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.
 But maybe I'm wrong and somebody can mentor you to do something useful
 with it -- there are so many advancements in PLs that I'm sure there
 must be something that can be done with PL/Java.

 Did you have a look at the TODO list? http://wiki.postgresql.org/wiki/Todo

However, the new user should be aware that many of the things in that
list are better described as to finish discussing/arguing whether we
want it or not, and what trade offs we are willing to make rather
than to do.

That was my experience, anyway.

Cheers,

Jeff

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Alvaro Herrera

Excerpts from Jeff Janes's message of mar mar 20 12:54:55 -0300 2012:

 On Mon, Mar 19, 2012 at 12:29 PM, Alvaro Herrera
 alvhe...@commandprompt.com wrote:

  Did you have a look at the TODO list? http://wiki.postgresql.org/wiki/Todo
 
 However, the new user should be aware that many of the things in that
 list are better described as to finish discussing/arguing whether we
 want it or not, and what trade offs we are willing to make rather
 than to do.
 
 That was my experience, anyway.

Feel free to edit the commentary at the top :-)

-- 
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The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma


-Original Message-
From: Merlin Moncure [mailto:mmonc...@gmail.com] 
Sent: 20 March 2012 20:52
To: Atri Sharma
Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
Page; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

sure:
first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
and take a look at all the various fdw projects.  they all utilize the
high level interfaces that postgresql provides to incorporate external
datasources and expose them you can query them as if they were views
or tables.  as you can see, this interface is popular with the
proliferation of projects to expose this or that.  what i'm thinking
is you make a fdw that invokes pl/java routines that make jdbc calls
out to external databases.  for fetching data and building sets.  as
long as you stick to vanilla jdbc calls, you then have a fdw that can
gather data from pretty much anything you can access via jdbc url
which is quite nice.

The fdw API is a C api, so you need to figure out how to proxy to your
pl/java calls where the real work is done -- I  haven't done that so
I'm not sure if this is even technically feasible.  If you can make
SPI calls from your fdw routines, that's one path through.   Tou have
lots of previous work to crib from though and hopefully there's a path
through.  As far as the ETL stuff I was talking about -- that was just
me thinking out loud...better to just get the basic mechanics working
up front..  For now, if you're interested in doing this, start
thinking about how to marry the fdw interface to pl/java...one you get
'hello world' there, it's all about where you want tot take it.

This is an interesting project -- you should entertain no illusions of
it making it into core, but if done right and completed it will raise
visibility of both pl/java and postgresql.

Merlin


---
Hi Merlin,

First of all,thanks a lot for the extensive reply and explanation.

The project seems very exciting,and I would consider it and honour to be
able to do it for PostGreSQL.

Basically,from what I understood,I will be building a fdw which will invoke
PL/Java routines which will make JDBC calls to external databases.So,the fdw
can be used to access any database that supports JDBC.That will be truly
awesome.

For connecting the C API and Pl/Java code,we can use JNI(Java Native
Interface).It's not too stable,but it can work if taken care of.

Please let me know how to proceed further.

Waiting for your reply,

Atri


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers


Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Merlin Moncure
On Tue, Mar 20, 2012 at 11:57 AM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 20:52
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

 sure:
 first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
 and take a look at all the various fdw projects.  they all utilize the
 high level interfaces that postgresql provides to incorporate external
 datasources and expose them you can query them as if they were views
 or tables.  as you can see, this interface is popular with the
 proliferation of projects to expose this or that.  what i'm thinking
 is you make a fdw that invokes pl/java routines that make jdbc calls
 out to external databases.  for fetching data and building sets.  as
 long as you stick to vanilla jdbc calls, you then have a fdw that can
 gather data from pretty much anything you can access via jdbc url
 which is quite nice.

 The fdw API is a C api, so you need to figure out how to proxy to your
 pl/java calls where the real work is done -- I  haven't done that so
 I'm not sure if this is even technically feasible.  If you can make
 SPI calls from your fdw routines, that's one path through.   Tou have
 lots of previous work to crib from though and hopefully there's a path
 through.  As far as the ETL stuff I was talking about -- that was just
 me thinking out loud...better to just get the basic mechanics working
 up front..  For now, if you're interested in doing this, start
 thinking about how to marry the fdw interface to pl/java...one you get
 'hello world' there, it's all about where you want tot take it.

 This is an interesting project -- you should entertain no illusions of
 it making it into core, but if done right and completed it will raise
 visibility of both pl/java and postgresql.

 Merlin


 ---
 Hi Merlin,

 First of all,thanks a lot for the extensive reply and explanation.

 The project seems very exciting,and I would consider it and honour to be
 able to do it for PostGreSQL.

 Basically,from what I understood,I will be building a fdw which will invoke
 PL/Java routines which will make JDBC calls to external databases.So,the fdw
 can be used to access any database that supports JDBC.That will be truly
 awesome.

 For connecting the C API and Pl/Java code,we can use JNI(Java Native
 Interface).It's not too stable,but it can work if taken care of.

That's backwards -- the C code will invoke java, not the other way
around -- so JNI is no help.  SPI is a C interface that allows you to
(in C) invoke any function in the database, including those written in
pl/java.  That's a possible path to doing

Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma


-Original Message-
From: Merlin Moncure [mailto:mmonc...@gmail.com] 
Sent: 20 March 2012 22:50
To: Atri Sharma
Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
Page; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Tue, Mar 20, 2012 at 11:57 AM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 20:52
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan;
Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave
Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

 sure:
 first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
 and take a look at all the various fdw projects.  they all utilize the
 high level interfaces that postgresql provides to incorporate external
 datasources and expose them you can query them as if they were views
 or tables.  as you can see, this interface is popular with the
 proliferation of projects to expose this or that.  what i'm thinking
 is you make a fdw that invokes pl/java routines that make jdbc calls
 out to external databases.  for fetching data and building sets.  as
 long as you stick to vanilla jdbc calls, you then have a fdw that can
 gather data from pretty much anything you can access via jdbc url
 which is quite nice.

 The fdw API is a C api, so you need to figure out how to proxy to your
 pl/java calls where the real work is done -- I  haven't done that so
 I'm not sure if this is even technically feasible.  If you can make
 SPI calls from your fdw routines, that's one path through.   Tou have
 lots of previous work to crib from though and hopefully there's a path
 through.  As far as the ETL stuff I was talking about -- that was just
 me thinking out loud...better to just get the basic mechanics working
 up front..  For now, if you're interested in doing this, start
 thinking about how to marry the fdw interface to pl/java...one you get
 'hello world' there, it's all about where you want tot take it.

 This is an interesting project -- you should entertain no illusions of
 it making it into core, but if done right and completed it will raise
 visibility of both pl/java and postgresql.

 Merlin


 ---
 Hi Merlin,

 First of all,thanks a lot for the extensive reply and explanation.

 The project seems very exciting,and I would consider it and honour to be
 able to do it for PostGreSQL.

 Basically,from what I understood,I will be building a fdw which will
invoke
 PL/Java routines which will make JDBC calls to external databases.So,the
fdw
 can be used to access any database that supports JDBC.That will be truly
 awesome.

 For connecting the C API and Pl/Java code,we can use JNI(Java Native
 Interface).It's not too

Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Merlin Moncure
On Tue, Mar 20, 2012 at 12:34 PM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 22:50
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 11:57 AM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 20:52
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan;
 Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave
 Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

 sure:
 first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
 and take a look at all the various fdw projects.  they all utilize the
 high level interfaces that postgresql provides to incorporate external
 datasources and expose them you can query them as if they were views
 or tables.  as you can see, this interface is popular with the
 proliferation of projects to expose this or that.  what i'm thinking
 is you make a fdw that invokes pl/java routines that make jdbc calls
 out to external databases.  for fetching data and building sets.  as
 long as you stick to vanilla jdbc calls, you then have a fdw that can
 gather data from pretty much anything you can access via jdbc url
 which is quite nice.

 The fdw API is a C api, so you need to figure out how to proxy to your
 pl/java calls where the real work is done -- I  haven't done that so
 I'm not sure if this is even technically feasible.  If you can make
 SPI calls from your fdw routines, that's one path through.   Tou have
 lots of previous work to crib from though and hopefully there's a path
 through.  As far as the ETL stuff I was talking about -- that was just
 me thinking out loud...better to just get the basic mechanics working
 up front..  For now, if you're interested in doing this, start
 thinking about how to marry the fdw interface to pl/java...one you get
 'hello world' there, it's all about where you want tot take it.

 This is an interesting project -- you should entertain no illusions of
 it making it into core, but if done right and completed it will raise
 visibility of both pl/java and postgresql.

 Merlin


 ---
 Hi Merlin,

 First of all,thanks a lot for the extensive reply and explanation.

 The project seems very exciting,and I would consider it and honour to be
 able to do it for PostGreSQL.

 Basically,from what I understood,I will be building a fdw which will
 invoke
 PL/Java routines which will make JDBC calls to external databases.So,the
 fdw
 can be used to access any database that supports JDBC.That will be truly
 awesome.

 For connecting

Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-20 Thread Atri Sharma
On Wed, Mar 21, 2012 at 12:42 AM, Merlin Moncure mmonc...@gmail.com wrote:
 On Tue, Mar 20, 2012 at 12:34 PM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 22:50
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan; Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 11:57 AM, Atri Sharma atri.j...@gmail.com wrote:


 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 20:52
 To: Atri Sharma
 Cc: Heikki Linnakangas; Alvaro Herrera; Daniel Farina; Andrew Dunstan;
 Dave
 Page; Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Tue, Mar 20, 2012 at 6:58 AM, Atri Sharma atri.j...@gmail.com wrote:
 -Original Message-
 From: Merlin Moncure [mailto:mmonc...@gmail.com]
 Sent: 20 March 2012 03:15
 To: Heikki Linnakangas
 Cc: Alvaro Herrera; Atri Sharma; Daniel Farina; Andrew Dunstan; Dave
 Page;
 Pg Hackers
 Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
 heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me.
 The
 last release was in September 2011, and there are active discussions on
 the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

 pl/java works pretty well and is somewhat widely used although it
 might need some more active maintainers.  just jumping into the
 project and nailing some old bugs and getting the juices flowing would
 be a tremendous help, as well as the less glamorous work of
 documentation and regular status updates.

 one pl/java based project that IMO is just screaming to be done is a
 pl/java based FDW (wrapping JDBC) that would approximately reproduce
 dblink...maybe with some extra features geared towards ETL type jobs
 like a row based callback for transformations in java.

 Merlin


 ---
 Hi Merlin

 Thanks for the idea.

 Could you please elaborate more on the project idea? It would be a great
 help for me.

 sure:
 first start here: http://wiki.postgresql.org/wiki/Foreign_data_wrappers
 and take a look at all the various fdw projects.  they all utilize the
 high level interfaces that postgresql provides to incorporate external
 datasources and expose them you can query them as if they were views
 or tables.  as you can see, this interface is popular with the
 proliferation of projects to expose this or that.  what i'm thinking
 is you make a fdw that invokes pl/java routines that make jdbc calls
 out to external databases.  for fetching data and building sets.  as
 long as you stick to vanilla jdbc calls, you then have a fdw that can
 gather data from pretty much anything you can access via jdbc url
 which is quite nice.

 The fdw API is a C api, so you need to figure out how to proxy to your
 pl/java calls where the real work is done -- I  haven't done that so
 I'm not sure if this is even technically feasible.  If you can make
 SPI calls from your fdw routines, that's one path through.   Tou have
 lots of previous work to crib from though and hopefully there's a path
 through.  As far as the ETL stuff I was talking about -- that was just
 me thinking out loud...better to just get the basic mechanics working
 up front..  For now, if you're interested in doing this, start
 thinking about how to marry the fdw interface to pl/java...one you get
 'hello world' there, it's all about where you want tot take it.

 This is an interesting project -- you should entertain no illusions of
 it making it into core, but if done right and completed it will raise
 visibility of both pl/java and postgresql.

 Merlin


 ---
 Hi Merlin,

 First of all,thanks a lot for the extensive reply and explanation.

 The project seems very exciting,and I would consider it and honour to be
 able to do it for PostGreSQL.

 Basically,from what I understood,I will be building a fdw which will
 invoke
 PL/Java routines which will make JDBC calls to external databases.So,the
 fdw
 can be used to access

Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Alvaro Herrera

Excerpts from Atri Sharma's message of dom mar 18 01:05:23 -0300 2012:

 I am understanding the scenario now. I will take a little of your time to
 modify my original idea:
 
 The middle layer still exists, but NOT on the individual client side ,
 rather , on the server side. That is, we maintain the middle layer on the
 server, and it is same for all the users. We can mutate the ordering, and
 changes would be reflected in all the clients, since they are all accessing
 the same middle layer, present on the server.

I will take a little of your time to ask whether you read the older
threads on the topic -- the one that Andrew Dunstan linked to, and the
older ones, to which that email links to?  This whole area has been
extensively discussed before.

In any case, I repeat what I said before: this is way too complex a
topic for it to make a good GSoC project (unless you're already
intimately familiar with the parser and executor code.)  You need to
pick something smaller, more localized.  

-- 
Álvaro Herrera alvhe...@commandprompt.com
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers


Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Atri Sharma
On Mon, Mar 19, 2012 at 11:51 PM, Alvaro Herrera
alvhe...@commandprompt.com wrote:

 Excerpts from Atri Sharma's message of dom mar 18 01:05:23 -0300 2012:

 I am understanding the scenario now. I will take a little of your time to
 modify my original idea:

 The middle layer still exists, but NOT on the individual client side ,
 rather , on the server side. That is, we maintain the middle layer on the
 server, and it is same for all the users. We can mutate the ordering, and
 changes would be reflected in all the clients, since they are all accessing
 the same middle layer, present on the server.

 I will take a little of your time to ask whether you read the older
 threads on the topic -- the one that Andrew Dunstan linked to, and the
 older ones, to which that email links to?  This whole area has been
 extensively discussed before.

 In any case, I repeat what I said before: this is way too complex a
 topic for it to make a good GSoC project (unless you're already
 intimately familiar with the parser and executor code.)  You need to
 pick something smaller, more localized.

 --
 Álvaro Herrera alvhe...@commandprompt.com
 The PostgreSQL Company - Command Prompt, Inc.
 PostgreSQL Replication, Consulting, Custom Development, 24x7 support


--

Hi Alvaro,

Thanks for your reply.Yes,I have read the earlier posts.

I am familiar with database systems.I have worked on them before and I
have done designing of some very basic databases.

Please guide me to some area where I can research for some gsoc project.

Thanks,

Atri


-- 
Regards,

Atri
l'apprenant

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers


Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Atri Sharma
On Tue, Mar 20, 2012 at 12:08 AM, Atri Sharma atri.j...@gmail.com wrote:
 On Mon, Mar 19, 2012 at 11:51 PM, Alvaro Herrera
 alvhe...@commandprompt.com wrote:

 Excerpts from Atri Sharma's message of dom mar 18 01:05:23 -0300 2012:

 I am understanding the scenario now. I will take a little of your time to
 modify my original idea:

 The middle layer still exists, but NOT on the individual client side ,
 rather , on the server side. That is, we maintain the middle layer on the
 server, and it is same for all the users. We can mutate the ordering, and
 changes would be reflected in all the clients, since they are all accessing
 the same middle layer, present on the server.

 I will take a little of your time to ask whether you read the older
 threads on the topic -- the one that Andrew Dunstan linked to, and the
 older ones, to which that email links to?  This whole area has been
 extensively discussed before.

 In any case, I repeat what I said before: this is way too complex a
 topic for it to make a good GSoC project (unless you're already
 intimately familiar with the parser and executor code.)  You need to
 pick something smaller, more localized.

 --
 Álvaro Herrera alvhe...@commandprompt.com
 The PostgreSQL Company - Command Prompt, Inc.
 PostgreSQL Replication, Consulting, Custom Development, 24x7 support


 --

 Hi Alvaro,

 Thanks for your reply.Yes,I have read the earlier posts.

 I am familiar with database systems.I have worked on them before and I
 have done designing of some very basic databases.

 Please guide me to some area where I can research for some gsoc project.

 Thanks,

 Atri


 --
 Regards,

 Atri
 l'apprenant


--
Hi Alvaro,

I was just going through PGfoundry and I think I will be able to work
on the PL/Java project.Please let me know If I can proceed further on
ot for GSOC and also,if currently there is any work that needs to be
done on PL/java.
-- 
Regards,

Atri
l'apprenant

-- 
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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Alvaro Herrera

Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.

Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.
But maybe I'm wrong and somebody can mentor you to do something useful
with it -- there are so many advancements in PLs that I'm sure there
must be something that can be done with PL/Java.

Did you have a look at the TODO list? http://wiki.postgresql.org/wiki/Todo

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Heikki Linnakangas

On 19.03.2012 21:29, Alvaro Herrera wrote:


Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:


I was just going through PGfoundry and I think I will be able to work
on the PL/Java project.Please let me know If I can proceed further on
ot for GSOC and also,if currently there is any work that needs to be
done on PL/java.


Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


I haven't followed PL/java either, but it doesn't look quite dead to me. 
The last release was in September 2011, and there are active discussions 
on the mailing lists. If it's not completely up-to-date with latest JDK 
and PostgreSQL releases, perhaps bringing it up-to-date and then adding 
some missing functionality would be a useful GSoC project.


I would suggest that you ask on the pl/java mailing list if there is 
something suitable for a GSoC project there, and if one of the pl/java 
developers would be willing to mentor.


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  EnterpriseDB   http://www.enterprisedb.com

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-19 Thread Merlin Moncure
On Mon, Mar 19, 2012 at 2:49 PM, Heikki Linnakangas
heikki.linnakan...@enterprisedb.com wrote:
 On 19.03.2012 21:29, Alvaro Herrera wrote:


 Excerpts from Atri Sharma's message of lun mar 19 16:20:09 -0300 2012:

 I was just going through PGfoundry and I think I will be able to work
 on the PL/Java project.Please let me know If I can proceed further on
 ot for GSOC and also,if currently there is any work that needs to be
 done on PL/java.


 Hm, I'm not sure on PL/Java.  As far as I know, it is a dead project.


 I haven't followed PL/java either, but it doesn't look quite dead to me. The
 last release was in September 2011, and there are active discussions on the
 mailing lists. If it's not completely up-to-date with latest JDK and
 PostgreSQL releases, perhaps bringing it up-to-date and then adding some
 missing functionality would be a useful GSoC project.

 I would suggest that you ask on the pl/java mailing list if there is
 something suitable for a GSoC project there, and if one of the pl/java
 developers would be willing to mentor.

pl/java works pretty well and is somewhat widely used although it
might need some more active maintainers.  just jumping into the
project and nailing some old bugs and getting the juices flowing would
be a tremendous help, as well as the less glamorous work of
documentation and regular status updates.

one pl/java based project that IMO is just screaming to be done is a
pl/java based FDW (wrapping JDBC) that would approximately reproduce
dblink...maybe with some extra features geared towards ETL type jobs
like a row based callback for transformations in java.

merlin

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Andrew Dunstan



On 03/17/2012 04:39 AM, Atri Sharma wrote:

Hi All,

I am Atri Sharma.I am a C developer with experience in database
designing and database management systems.I have worked with
MySql,Oracle and other database systems.I have designed databases for
various projects as well.

I would be interested in developing the column reordering project by a
single ALTER command.I have an idea in mind that would solve
theproblem in a very easy way.

Please let me know how to proceed further on this.




You should review the history on this. See 
http://archives.postgresql.org/message-id/1324412114-sup-9...@alvh.no-ip.org 
as a good place to start.



You should be aware that anything that doesn't follow the previous 
discussions is likely to be rejected. But if you can do something that 
does implement what was previously discussed, that would be awesome.


cheers

andrew

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma
Thanks Andrew.

I went through the link. Here is my idea:

I believe we can build a middle layer that encapsulates the physical
details from the user and gives him/her a VIEW that is actually generated by
the system itself. That means, we have a system such as:

LOGICAL LAYER
--
MIDDLE LAYER
--
PHYSICAL LAYER.

Now, the punch would be, the middle layer would be on the client. The middle
layer is more of an interface for the user which he/she can completely
customize.

Now, what is actually happening is that each component is mapped to their
physical address. I am planning to make a struct which will be the mapping
between the physical address and the logical address.I have not yet decided
on the design of the struct,but I plan an id , the type and the physical
address.When a component is used in the middle layer,it is represented in an
instantiation of the struct which is unchangeable throughout.Whenever we
need to customize the middle layer,we just need to reorder the components.

For our specific case,the reordering of table columns,we need not change the
schema or the physical ordering.All we need to do is,reorder the
components.One ALTER statement(with added customized clauses) will do the
reordering.The mapping remains constant,because,the struct instantiations of
the components remain constant,hence,the mapping remains constant and we can
access the physical address of any component at any time.

Please let me know your feedback on the idea.

Atri

-Original Message-
From: Andrew Dunstan [mailto:and...@dunslane.net] 
Sent: 17 March 2012 21:30
To: Atri Sharma
Cc: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012



On 03/17/2012 04:39 AM, Atri Sharma wrote:
 Hi All,

 I am Atri Sharma.I am a C developer with experience in database
 designing and database management systems.I have worked with
 MySql,Oracle and other database systems.I have designed databases for
 various projects as well.

 I would be interested in developing the column reordering project by a
 single ALTER command.I have an idea in mind that would solve
 theproblem in a very easy way.

 Please let me know how to proceed further on this.



You should review the history on this. See 
http://archives.postgresql.org/message-id/1324412114-sup-9...@alvh.no-ip.or
g 
as a good place to start.


You should be aware that anything that doesn't follow the previous 
discussions is likely to be rejected. But if you can do something that 
does implement what was previously discussed, that would be awesome.

cheers

andrew


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma
Hi all,

In follow up to my last mail, attached below, for performance, we can build
a graph with edges having weight in sense of performance wise and padding
saving wise . Then , we can build a minimal spanning tree, and the tree
generated would be our order of columns . When any changes are made ,
changes in the graph will be done and minimal spanning tree would be
recomputed.

Atri

-Original Message-
From: Atri Sharma [mailto:atri.j...@gmail.com] 
Sent: 17 March 2012 22:43
To: 'Andrew Dunstan'
Cc: 'pgsql-hackers@postgresql.org'
Subject: RE: [HACKERS] Regarding column reordering project for GSoc 2012

Thanks Andrew.

I went through the link. Here is my idea:

I believe we can build a middle layer that encapsulates the physical
details from the user and gives him/her a VIEW that is actually generated by
the system itself. That means, we have a system such as:

LOGICAL LAYER
--
MIDDLE LAYER
--
PHYSICAL LAYER.

Now, the punch would be, the middle layer would be on the client. The middle
layer is more of an interface for the user which he/she can completely
customize.

Now, what is actually happening is that each component is mapped to their
physical address. I am planning to make a struct which will be the mapping
between the physical address and the logical address.I have not yet decided
on the design of the struct,but I plan an id , the type and the physical
address.When a component is used in the middle layer,it is represented in an
instantiation of the struct which is unchangeable throughout.Whenever we
need to customize the middle layer,we just need to reorder the components.

For our specific case,the reordering of table columns,we need not change the
schema or the physical ordering.All we need to do is,reorder the
components.One ALTER statement(with added customized clauses) will do the
reordering.The mapping remains constant,because,the struct instantiations of
the components remain constant,hence,the mapping remains constant and we can
access the physical address of any component at any time.

Please let me know your feedback on the idea.

Atri

-Original Message-
From: Andrew Dunstan [mailto:and...@dunslane.net] 
Sent: 17 March 2012 21:30
To: Atri Sharma
Cc: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012



On 03/17/2012 04:39 AM, Atri Sharma wrote:
 Hi All,

 I am Atri Sharma.I am a C developer with experience in database
 designing and database management systems.I have worked with
 MySql,Oracle and other database systems.I have designed databases for
 various projects as well.

 I would be interested in developing the column reordering project by a
 single ALTER command.I have an idea in mind that would solve
 theproblem in a very easy way.

 Please let me know how to proceed further on this.



You should review the history on this. See 
http://archives.postgresql.org/message-id/1324412114-sup-9...@alvh.no-ip.or
g 
as a good place to start.


You should be aware that anything that doesn't follow the previous 
discussions is likely to be rejected. But if you can do something that 
does implement what was previously discussed, that would be awesome.

cheers

andrew


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Alvaro Herrera

Excerpts from Atri Sharma's message of sáb mar 17 05:39:10 -0300 2012:
 Hi All,
 
 I am Atri Sharma.I am a C developer with experience in database
 designing and database management systems.I have worked with
 MySql,Oracle and other database systems.I have designed databases for
 various projects as well.
 
 I would be interested in developing the column reordering project by a
 single ALTER command.I have an idea in mind that would solve
 theproblem in a very easy way.

This is far too complex to be done in a GSoC project.

I don't see how having a middle layer client-side would fix anything.
You'd need to explain how it'd work, but to me that description sounds
bogus.

-- 
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The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma
HI Alvaro,
I did send a complete description to the mailing list, based on your past 
discussions. I don’t know if you got it.

Please let me know if I should re-send the mail trail.

Atri

-Original Message-
From: Alvaro Herrera [mailto:alvhe...@commandprompt.com] 
Sent: 18 March 2012 00:17
To: Atri Sharma
Cc: Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012


Excerpts from Atri Sharma's message of sáb mar 17 05:39:10 -0300 2012:
 Hi All,
 
 I am Atri Sharma.I am a C developer with experience in database
 designing and database management systems.I have worked with
 MySql,Oracle and other database systems.I have designed databases for
 various projects as well.
 
 I would be interested in developing the column reordering project by a
 single ALTER command.I have an idea in mind that would solve
 theproblem in a very easy way.

This is far too complex to be done in a GSoC project.

I don't see how having a middle layer client-side would fix anything.
You'd need to explain how it'd work, but to me that description sounds
bogus.

-- 
Álvaro Herrera alvhe...@commandprompt.com
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Alvaro Herrera

Excerpts from Atri Sharma's message of sáb mar 17 15:48:13 -0300 2012:
 
 HI Alvaro,
 I did send a complete description to the mailing list, based on your past 
 discussions. I don’t know if you got it.

I read it, but I don't see how is the client involved.

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma
Hi Alvaro,
Thanks for going through my description.


I was going through the posts,when I realised that if we give each client the 
flexibility of defining his/her own order with complete control,that would be 
probably the right way(IMHO).

I mean,if the user sees,not the physical implementation,but a customizable 
interface instead,which is mapped to the physical implementation,then,we can 
solve to some extent,the problem of logical/physical decoupling.

If you are free,I can come on IRC right now and explain my idea to you.

Atri 


-Original Message-
From: Alvaro Herrera [mailto:alvhe...@commandprompt.com] 
Sent: 18 March 2012 00:34
To: Atri Sharma
Cc: Pg Hackers
Subject: RE: [HACKERS] Regarding column reordering project for GSoc 2012


Excerpts from Atri Sharma's message of sáb mar 17 15:48:13 -0300 2012:
 
 HI Alvaro,
 I did send a complete description to the mailing list, based on your past 
 discussions. I don’t know if you got it.

I read it, but I don't see how is the client involved.

-- 
Álvaro Herrera alvhe...@commandprompt.com
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Dave Page
On Saturday, March 17, 2012, Atri Sharma atri.j...@gmail.com wrote:
 Hi Alvaro,
 Thanks for going through my description.


 I was going through the posts,when I realised that if we give each client
the flexibility of defining his/her own order with complete control,that
would be probably the right way(IMHO).

 I mean,if the user sees,not the physical implementation,but a
customizable interface instead,which is mapped to the physical
implementation,then,we can solve to some extent,the problem of
logical/physical decoupling.

Anything done in the client bar changing the column it orders on (which
ideally should be avoided too if practical) is going to lead to pain and
suffering as some will do it, some won't, and a few might get it wrong.

-- 
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma
Hi Dave,

 

I believe,with the ALTER command,we plan to give the user power to modify
ordering . Don't we?

 

Atri

 

From: Dave Page [mailto:dp...@pgadmin.org] 
Sent: 18 March 2012 00:46
To: Atri Sharma
Cc: Alvaro Herrera; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

 



On Saturday, March 17, 2012, Atri Sharma atri.j...@gmail.com wrote:
 Hi Alvaro,
 Thanks for going through my description.


 I was going through the posts,when I realised that if we give each client
the flexibility of defining his/her own order with complete control,that
would be probably the right way(IMHO).

 I mean,if the user sees,not the physical implementation,but a customizable
interface instead,which is mapped to the physical implementation,then,we can
solve to some extent,the problem of logical/physical decoupling.

Anything done in the client bar changing the column it orders on (which
ideally should be avoided too if practical) is going to lead to pain and
suffering as some will do it, some won't, and a few might get it wrong.

-- 
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Jaime Casanova
On Sat, Mar 17, 2012 at 2:16 PM, Atri Sharma atri.j...@gmail.com wrote:
 Hi Dave,

 I believe,with the ALTER command,we plan to give the user power to modify
 ordering . Don’t we?


And how is that different from a view that orders the columns as the
user wishes?

-- 
Jaime Casanova         www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Andrew Dunstan



On 03/17/2012 03:07 PM, Atri Sharma wrote:

Hi Alvaro,
Thanks for going through my description.


I was going through the posts,when I realised that if we give each client the 
flexibility of defining his/her own order with complete control,that would be 
probably the right way(IMHO).

I mean,if the user sees,not the physical implementation,but a customizable 
interface instead,which is mapped to the physical implementation,then,we can 
solve to some extent,the problem of logical/physical decoupling.


I think your design is a complete non-starter. Please review what was 
previously discussed. If you're not going to attempt that then my strong 
advice is to try a different project.




If you are free,I can come on IRC right now and explain my idea to you.



The place to discuss designs is on the mailing lists. That's the way we 
do things. The vast majority of hackers are not to be found in IRC.


cheers

andrew


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Andrew Dunstan



On 03/17/2012 04:42 PM, Dave Page wrote:



On Saturday, March 17, 2012, Atri Sharma atri.j...@gmail.com 
mailto:atri.j...@gmail.com wrote:

 Hi Dave,



 I believe,with the ALTER command,we plan to give the user power to 
modify ordering . Don’t we?


Probably, but that's not relevant to my point as far as I can see - I 
was objecting to your suggestion that the middle layer that 
translates the physical to logical ordering and vice-versa (if I 
understood your description correctly) be in the client.





Mine too. We don't want a column ordering that's different for everyone. 
That's a recipe for mass confusion. We want to be able to mutate the 
ordering for everyone, and for everyone to see the same ordering. That 
means it MUST be done purely in the backend (as indeed all ALTER TABLE 
commands must be.)


cheers

andrew

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Daniel Farina
On Sat, Mar 17, 2012 at 1:48 PM, Andrew Dunstan and...@dunslane.net wrote:
 Mine too. We don't want a column ordering that's different for everyone.
 That's a recipe for mass confusion. We want to be able to mutate the
 ordering for everyone, and for everyone to see the same ordering. That means
 it MUST be done purely in the backend (as indeed all ALTER TABLE commands
 must be.)

I am in agreement.  This state would have to live in the session
between client and server, so that semantic analysis could do the
right thing by looking at the environment on the backend, too.  Life
is already really difficult because of session state: consider
connection poolers, which are both common and have subtle caveats that
are close to being completely silent if one uses the wrong construct.
The only reason people get away with this in practice is because most
of them do not use constructs like temp tables and dblink in
conjunction with pooling, but if they did, the prospect of what could
happen when sessions get crossed is a nightmare (clearly, I'd like a
way to treat this, because session state is also useful, but that's
not the here and now...)

Reordering attributes totally backends-side, though, would be a
wonderful feature, and already has plenty of work just to realize the
physical/logical decoupling in the backend, so I have a lot of
enthusiasm for the project in general.

-- 
fdr

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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma


-Original Message-
From: Daniel Farina [mailto:dan...@heroku.com] 
Sent: 18 March 2012 06:30
To: Andrew Dunstan
Cc: Dave Page; Atri Sharma; Alvaro Herrera; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Sat, Mar 17, 2012 at 1:48 PM, Andrew Dunstan and...@dunslane.net wrote:
 Mine too. We don't want a column ordering that's different for everyone.
 That's a recipe for mass confusion. We want to be able to mutate the
 ordering for everyone, and for everyone to see the same ordering. That
means
 it MUST be done purely in the backend (as indeed all ALTER TABLE commands
 must be.)

I am in agreement.  This state would have to live in the session
between client and server, so that semantic analysis could do the
right thing by looking at the environment on the backend, too.  Life
is already really difficult because of session state: consider
connection poolers, which are both common and have subtle caveats that
are close to being completely silent if one uses the wrong construct.
The only reason people get away with this in practice is because most
of them do not use constructs like temp tables and dblink in
conjunction with pooling, but if they did, the prospect of what could
happen when sessions get crossed is a nightmare (clearly, I'd like a
way to treat this, because session state is also useful, but that's
not the here and now...)

Reordering attributes totally backends-side, though, would be a
wonderful feature, and already has plenty of work just to realize the
physical/logical decoupling in the backend, so I have a lot of
enthusiasm for the project in general.

-- 
Fdr

---

Hi All,

First of all, thanks a million for all the wonderful feedbacks. It has
really taught me a lot in just 8 hours.

I am understanding the scenario now. I will take a little of your time to
modify my original idea:

The middle layer still exists, but NOT on the individual client side ,
rather , on the server side. That is, we maintain the middle layer on the
server, and it is same for all the users. We can mutate the ordering, and
changes would be reflected in all the clients, since they are all accessing
the same middle layer, present on the server.

The mapping structure, according to me, should still remain the same.

Please let me know your feedback and corrections.

Atri


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Re: [HACKERS] Regarding column reordering project for GSoc 2012

2012-03-17 Thread Atri Sharma


-Original Message-
From: jcasa...@systemguards.com.ec [mailto:jcasa...@systemguards.com.ec] On
Behalf Of Jaime Casanova
Sent: 18 March 2012 01:04
To: Atri Sharma
Cc: Dave Page; Alvaro Herrera; Pg Hackers
Subject: Re: [HACKERS] Regarding column reordering project for GSoc 2012

On Sat, Mar 17, 2012 at 2:16 PM, Atri Sharma atri.j...@gmail.com wrote:
 Hi Dave,

 I believe,with the ALTER command,we plan to give the user power to modify
 ordering . Don’t we?


And how is that different from a view that orders the columns as the
user wishes?

-- 
Jaime Casanova         www.2ndQuadrant.com
Professional PostgreSQL: Soporte 24x7 y capacitación

--

Hi Jaime ,

Well, I believe, my idea is more towards the layers already present in
database systems, rather than views.

1) Views are just a window to some(or all) part of a database. There are
many restriction on views, none of which are applicable to our middle layer.
This is so because, even though the middle layer is encapsulating the
addressing and mapping details from the user , it still provides complete
access and rights to the database according to the user's privilege level.

2) Views are optional, wherever our middle layer is built right in the
database. It is not optional. User can only see the middle layer. It cannot
directly interact with the underlying layers.

Please let me know your feedback and comments.

Atri


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