Queries hang when accessing Oracle via ODBC and Python

ODBC is a client tool and does not affect the way that Postgresql verifies access. I don't know if its any different for a postgresql server on windows, but in linux, there is a file called pg_hba.conf. This file is usually located in the data directory of the server install. In Linux, you typically find it in /var/lib/pgsql/data/.

This file allows you to define which ip addresses can access your postgresql server and how they may access it. Types of access include trust (no password), md5 (password), etc.

So for example, if your access users are on say 192.168.0.10 and you want them to use a password you would add this entry.

# TYPE  DATABASE    USER        IP-ADDRESS    IP-MASK             METHOD
host    all         access_user         192.168.0.10    255.255.255.255     md5     

In postgresql you would then have to create the user and give him the ability to login.

1. psql -d nameofdatabase
2. CREATE ROLE access_user WITH LOGIN PASSWORD 'jw8s0F4';
3. GRANT SELECT ON nameoftable TO access_user;

Good luck

You have created a linked server, not a linked database, so there is no list of databases to select from. You need to either use a "four-part name" or use the OPENQUERY() function.

Four-part names describe an object on another server. Usually a four-part name would look like "servername.databasename.schemaname.tablename", but for Oracle you apparently need to leave the database name out. A query using a four-part name for Oracle might look like this:

SELECT name FROM OracleSvr..joe.titles WHERE id = 101

where "OracleSvr" is the name of the linked server.

Alternatively, here is an example of a statement that uses OPENQUERY. It should do the same thing, some people find this style easier to read.

SELECT * FROM OPENQUERY (OracleSvr, 'SELECT name FROM joe.titles WHERE id = 101')

OPENQUERY is documented here.

No matter which style of query you choose, you would connect via your Python program to the SQL Server and then run the query.

You can do this via ODBC, you don't need to specify the database name when setting up the connection, you do it at query time as described above.