Tom Lane wrote:
> Joe Conway <joseph.conway@home.com> writes:
>
>>I confirmed the UNION hack is no longer required. Thanks! Is it too late
>>to change the README in contrib/dblink?
>>
>
> No, I don't think that's a problem. Send a patch.
>
Here's a (documentation only) patch for the contrib/dblink README.
Thanks,
Joe
*** README.dblink.orig Mon Jun 18 12:09:50 2001
--- README.dblink Wed Dec 12 19:57:34 2001
***************
*** 82,88 ****
Example usage
! select dblink('hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd','select f1, f2 from
mytable');
==================================================================
--- 82,89 ----
Example usage
! select dblink('hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd'
! ,'select f1, f2 from mytable');
==================================================================
***************
*** 118,161 ****
==================================================================
! NOTE: If you need to provide selection criteria in a WHERE clause, it is necessary
! to 'fake' a UNION, e.g.
! select
! dblink_tok(t1.dblink_p,0) as f1
! ,dblink_tok(t1.dblink_p,1) as f2
! from
! (
! select dblink(
! 'hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd'
! ,'select f1, f2 from mytable'
! ) as dblink_p
! union all
! select null where false
! ) as t1
! where
! dblink_tok(t1.dblink_p,0) = 'mycriteria';
!
! in order to work around an issue with the query optimizer. A more convenient way to approach
! this problem is to create a view:
!
! create view myremotetable as
! select
! dblink_tok(t1.dblink_p,0) as f1
! ,dblink_tok(t1.dblink_p,1) as f2
! from
! (
! select dblink(
! 'hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd'
! ,'select f1, f2 from mytable'
! ) as dblink_p
! union all
! select null where false
! ) as t1;
Then you can simply write:
! select f1,f2 from myremotetable where f1 = 'mycriteria';
==================================================================
--- 119,134 ----
==================================================================
! A more convenient way to use dblink may be to create a view:
! create view myremotetable as
! select dblink_tok(t1.dblink_p,0) as f1, dblink_tok(t1.dblink_p,1) as f2
! from (select dblink('hostaddr=127.0.0.1 port=5432 dbname=template1 user=postgres password=postgres'
! ,'select proname, prosrc from pg_proc') as dblink_p) as t1;
Then you can simply write:
! select f1, f2 from myremotetable where f1 like 'bytea%';
==================================================================
