Can't you use this?
select name from database2.sr_1 where name not in (select name from database2.pr_1); My test database VM isn't running so I can't test it, but I seem to remember that that's how I did it for a few queries of that type. This is assuming the 2 databases are running on the same machine, like the way there is template0 as the default and you add addition databases to the same 'instance'. If you are talking about 2 different database servers, then I have no idea. Edward W. Rouse From: pgsql-sql-ow...@postgresql.org [mailto:pgsql-sql-ow...@postgresql.org] On Behalf Of Nicholas I Sent: Thursday, April 30, 2009 6:12 AM To: Joshua Tolley Cc: Adam Ruth; Pawel Socha; pgsql-sql@postgresql.org Subject: Re: [SQL] Comparing two tables of different database Hi All, For example, There are two database. database1 and database 2; database1 has a table called pr_1 with the columns, id,name and time. database2 has a table called sr_1 with the_columns id,name and time. i would like to find out the differences that is, find the names that are not in sr_1 but in pr_1. we can achieve this by the query, select name from sr_1 where name not in (select name from pr_1); the above query will work in case of two tables in the same database. But the problem is, these two tables are in different database. i did not understand about the dblink. is there any exaples on dblink. can we do it without using dblink. -Nicholas I On Thu, Apr 30, 2009 at 9:07 AM, Joshua Tolley <eggyk...@gmail.com> wrote: On Thu, Apr 30, 2009 at 08:20:02AM +1000, Adam Ruth wrote: > The simple answer is to pg_dump both tables and compare the output with > diff. > Other than that, I think you'll need a custom program. For all but the strictest definition of "identical", that won't work. Tables may easily contain the same information, in different on-disk order, and pg_dump will most likely give the data to you in an order similar to its ordering on disk. Something like a COPY (<query>) TO <file>, where <query> includes an ORDER BY clause, might give you a suitable result from both tables, on which you could then take a checksum. - Josh / eggyknap -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkn5HQoACgkQRiRfCGf1UMPcagCfQDRa2bXPRjgSuVsrFYTnGTTC rhoAnAlGwp0vSKd2uspyFvxCTfugG6Yh =LO6r -----END PGP SIGNATURE-----
