Re: [BUGS] BUG #6660: losing schema name in pg_dump

2012-05-23 Thread Chaitany Kulkarni
Sorry for the late reply. But after comparing output results of pg_dump and
other tools in SQL format, I think it will helpful if an another switch is
provided in pg_dump to output data and definition of objects of only given
type.

e.g.
pg_dump --type views

It will export only views in given format for given other options such as
database, schema etc. Currently pg_dump supports to export the objects as
per the list but it is very difficult to list few hundred items there. So
it will be helpful when definitions and data of only certain types from a
schema are needed.

For SCM, I am looking for various options but SCM do not provide tools to
compare objects from two or more databases and database developers need
more options to manage database objects. Many times clients can change the
object definitions as per there needs and it becomes very hard to maintain
a version for each customer for a product. So looking to use Extension
mechanism or some thing else.

Thanks and regards,

C P Kulkarni


On Wed, May 23, 2012 at 11:11 PM, Chaitany Kulkarni
wrote:

> On Tue, May 22, 2012 at 8:33 PM, Tom Lane  wrote:
>
>> Chaitany Kulkarni  writes:
>> > I didn't understand  when user have defined schema names explicitly in
>> > definition of the objects and most database developers insist on writing
>> > schema names explicitly, why pg_dump is not outputting it as it is.
>>
>> The short answer to that is that the internal representation of views
>> and other objects only stores object identities, not how they were named
>> in the input.  We don't store whitespace or layout choices either, and
>> there are various other ways that the output can vary from what you
>> typed.  So really, if you're intent on that, keeping the original source
>> file is the way to go.
>>
>>regards, tom lane
>>
>
>
>
>
> --
> Chaitanya P. Kulkarni
>
> Copyright. All rights are reserved for any object, text, ideas, images and
> any other things.
> ---
> Keep your Environment clean and green.
> --xox
>
>


-- 
Chaitanya P. Kulkarni

Copyright. All rights are reserved for any object, text, ideas, images and
any other things.
---
Keep your Environment clean and green.
--xox


Re: [BUGS] BUG #6660: losing schema name in pg_dump

2012-05-22 Thread Tom Lane
Chaitany Kulkarni  writes:
> I didn't understand  when user have defined schema names explicitly in
> definition of the objects and most database developers insist on writing
> schema names explicitly, why pg_dump is not outputting it as it is.

The short answer to that is that the internal representation of views
and other objects only stores object identities, not how they were named
in the input.  We don't store whitespace or layout choices either, and
there are various other ways that the output can vary from what you
typed.  So really, if you're intent on that, keeping the original source
file is the way to go.

regards, tom lane

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


Re: [BUGS] BUG #6660: losing schema name in pg_dump

2012-05-22 Thread Chaitany Kulkarni
Thanks for your reply.
I know that pg_dump is not intended to provide SQL script to be working in
many other DBMS. But even if I have to dump all functions/views (tables and
other objects are not changed a lot like functions/views due to changes in
business rules or behaviour) from a certain schema with explicit schema
names and if I have objects with same name in other schemas which are also
part of the search_path then it creates a problem.
I didn't understand  when user have defined schema names explicitly in
definition of the objects and most database developers insist on writing
schema names explicitly, why pg_dump is not outputting it as it is. I know
that using SCM is better but many times such object definitions are
directly transferred to clients without SCM and it can create problems when
using same object names in multiple schemas.

Now I got details about pg_get_functiondef(oid) from pg_catalog which
outputs the definitions of functions as it is. So thanks a lot. It will be
still helpful not omit schema name when explicitly defined. You are also
requested to give more details about why t is more convenient to omit
schema names?

Regards,
C P Kulkarni




On Tue, May 22, 2012 at 7:09 PM, Tom Lane  wrote:

> shreeseva...@gmail.com writes:
> > Many times I have to dump all objects from a schema (single schema
> holding
> > only functions and views) in plain text format. It is found that pg_dump
> > includes a set search_path statement at the beginning and drops all
> > occurrences of the schema name (to which dumped object belongs) from
> > function/view bodies even if they are explicitly defined while creating
> > functions/views.
>
> This is not a bug.  It's intentional behavior and is convenient more
> often than not.
>
> > This makes it problematic to maintain the software available for another
> > RDBMS as for most other RDBMS we have to explicitly define schema names
> > always.
>
> This claim seems quite baseless.  You certainly haven't offered any
> actual evidence of a situation where omitting unnecessary schema names
> is problematic.
>
> More generally, though, pg_dump has never attempted to promise that its
> output can be loaded into other DBMSes without pain, and it would be
> practically impossible to make such a promise; there are too many subtle
> differences in the various dialects of SQL.  If you have SQL that is
> intended to work in multiple DBMSes, you would be best advised to
> maintain it as text files (perhaps in an SCM) rather than hope that
> pg_dump's output will still be useful for the other systems.
>
>regards, tom lane
>



-- 
Chaitanya P. Kulkarni

Copyright. All rights are reserved for any object, text, ideas, images and
any other things.
---
Keep your Environment clean and green.
--xox


Re: [BUGS] BUG #6660: losing schema name in pg_dump

2012-05-22 Thread Tom Lane
shreeseva...@gmail.com writes:
> Many times I have to dump all objects from a schema (single schema holding
> only functions and views) in plain text format. It is found that pg_dump
> includes a set search_path statement at the beginning and drops all
> occurrences of the schema name (to which dumped object belongs) from
> function/view bodies even if they are explicitly defined while creating
> functions/views.

This is not a bug.  It's intentional behavior and is convenient more
often than not.

> This makes it problematic to maintain the software available for another
> RDBMS as for most other RDBMS we have to explicitly define schema names
> always. 

This claim seems quite baseless.  You certainly haven't offered any
actual evidence of a situation where omitting unnecessary schema names
is problematic.

More generally, though, pg_dump has never attempted to promise that its
output can be loaded into other DBMSes without pain, and it would be
practically impossible to make such a promise; there are too many subtle
differences in the various dialects of SQL.  If you have SQL that is
intended to work in multiple DBMSes, you would be best advised to
maintain it as text files (perhaps in an SCM) rather than hope that
pg_dump's output will still be useful for the other systems.

regards, tom lane

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