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Thread: Select between two databases

Select between two databases

From
Indraneel Majumdar
Date:
Hi,

Does any one know how I may select between two databases running on same
machine or on different machines eg.

select colA1 from tableA1 where colA2 in (select colB1 from tableB1);

here tableA1 and tableB1 are in different databases. The two databases
might be under the same postmaster or on different machines under
different postmasters. How do I query both simultaneously? Is it possible?

Thanks,
Indraneel

/************************************************************************.
# Indraneel Majumdar                  ¡  E-mail: indraneel@123india.com  #
# Bioinformatics Unit (EMBNET node),  ¡  URL: http://scorpius.iwarp.com  #
# Centre for DNA Fingerprinting and Diagnostics,                         #
# Hyderabad, India - 500076                                              #
`************************************************************************/

Re: Select between two databases

From
Fredrick Bartlett
Date:
Not sure if same can be accomplished with different servers.
Try the following for database's on one server,  use alias & dot notation...

select a1.colA1 from
myDatabase1.tableA1 a1
where a1.A2 in (select b1.colB1 from myDatabase2.tableB1 b1)

Indraneel Majumdar wrote:

> Hi,
>
> Does any one know how I may select between two databases running on same
> machine or on different machines eg.
>
> select colA1 from tableA1 where colA2 in (select colB1 from tableB1);
>
> here tableA1 and tableB1 are in different databases. The two databases
> might be under the same postmaster or on different machines under
> different postmasters. How do I query both simultaneously? Is it possible?
>
> Thanks,
> Indraneel
>
> /************************************************************************.
> # Indraneel Majumdar                  ¡  E-mail: indraneel@123india.com  #
> # Bioinformatics Unit (EMBNET node),  ¡  URL: http://scorpius.iwarp.com  #
> # Centre for DNA Fingerprinting and Diagnostics,                         #
> # Hyderabad, India - 500076                                              #
> `************************************************************************/

Re: Select between two databases

From
Indraneel Majumdar
Date:
Not working, but thanks anyway. Can anyone point out the relevant area of
the source where queries are handled?

Thanks,
Indraneel 

On Sun, 24 Sep 2000, Fredrick Bartlett wrote:

> Not sure if same can be accomplished with different servers.
> Try the following for database's on one server,  use alias & dot notation...
> 
> select a1.colA1 from
> myDatabase1.tableA1 a1
> where a1.A2 in (select b1.colB1 from myDatabase2.tableB1 b1)
> 

/************************************************************************.
# Indraneel Majumdar                  ¡  E-mail: indraneel@123india.com  #
# Bioinformatics Unit (EMBNET node),  ¡  URL: http://scorpius.iwarp.com  #
# Centre for DNA Fingerprinting and Diagnostics,                         #
# Hyderabad, India - 500076                                              #
`************************************************************************/

Re: Select between two databases

From
Stephan Szabo
Date:
On Sun, 24 Sep 2000, Indraneel Majumdar wrote:

> Does any one know how I may select between two databases running on same
> machine or on different machines eg.
> 
> select colA1 from tableA1 where colA2 in (select colB1 from tableB1);
> 
> here tableA1 and tableB1 are in different databases. The two databases
> might be under the same postmaster or on different machines under
> different postmasters. How do I query both simultaneously? Is it possible?

Currently postgres databases may not be spanned in queries.

From
Keith Wong
Date:
Hi ppl,

Just wondering if anyone knows if its possible to set the transaction 
isolation
level from inside a stored procedure in plpgsql. Or do I need to run the 
'set transaction
isolation level' command before I called the stored procedure? I'm not even 
sure that
would work, I assume plpgsql uses the current transaction isolation level?

Any help would be much appreciated :)

Cheers, Keith.