Обсуждение: Queries across multiple database
I am in the process of migrating the databases for an application from mysql to postgres. The application is uses several different databases. From what I have read, postgres still does not support queries across multiple databases. If this is still true, does anyone have any tricks to get around this? I'm sure this is a common problem for people migrating from mysql. The obvious answer is to just migrate everything into one larger postgres database, but I would like to avoid this if possible - many a line of could would need to be touched if this was done. Thanks, Garth
Although postgres itself doesn't seem to have a thing such as Informix' "synonym" which allows more-or-less transparent accessto a table in a remote database, there is a utility in contrib directory of the postgres source called dblink, whichallows access to different instance of postgres by opening connections. I have only played with it for testing and haveno idea of its limitations, but it might serve your needs. Greg Williamson DBA GlobeXplorer LLC -----Original Message----- From: Garth Thompson [mailto:garth@opsource.net] Sent: Wednesday, June 30, 2004 3:54 PM To: pgsql-sql@postgresql.org Subject: [SQL] Queries across multiple database I am in the process of migrating the databases for an application from mysql to postgres. The application is uses several different databases. From what I have read, postgres still does not support queries across multiple databases. If this is still true, does anyone have any tricks to get around this? I'm sure this is a common problem for people migrating from mysql. The obvious answer is to just migrate everything into one larger postgres database, but I would like to avoid this if possible - many a line of could would need to be touched if this was done. Thanks, Garth ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
On Wed, 2004-06-30 at 18:54, Garth Thompson wrote: > I am in the process of migrating the databases for an application from mysql > to postgres. The application is uses several different databases. From > what I have read, postgres still does not support queries across multiple > databases. If this is still true, does anyone have any tricks to get around > this? I'm sure this is a common problem for people migrating from mysql. > The obvious answer is to just migrate everything into one larger postgres > database, but I would like to avoid this if possible - many a line of could > would need to be touched if this was done. In this case, a PostgreSQL Schema is essentially the same as a MySQL Database. Use one database, and multiple schemas.