How to create a transparent gateway in Oracle

There are many methods to migrate data from SQL Server 2000 to Oracle recently, but they have their own advantages and disadvantages.

The first method is to use DTS provided by ms SQL Server for migration, which is very useful. However, fields of the image type cannot be imported using DTS and the data volume is large, memory overflow may occur. A computer with 2 GB of memory can be dragged to death.

The second method is to use the transparent gateway of Oracle, and then create a link to SQL Server, through which you can access SQL server data, the following describes how to create a transparent gateway on an ORACLE Server.

1 first of all, of course, to install the tg4msql (Oracle transparent gateway for ms SQL Server) tool, you need to customize the installation, the installed Oracle 9i can still repair installation.

2 $ oracle9i_home/tg4msql/admin to modify the inittg4msql. ora file:

Hs_fds_connect_info = "Server = sqlserver_hostname; database = pubs"
Hs_fds_trace_level = off
Hs_fds_recovery_account = recover
Hs_fds_recovery_pwd = recover

3. modify the content of listener. ora and add a section in sid_list_listener:

(Sid_desc =
(Sid_name = pubs)
(ORACLE_HOME = D:/Oracle/ora92)
(Program = tg4msql)
)
4. Restart the tnslistener Service

5. modify the content of tnsnames. ora and add a section:

Pubs =
(Description =
(Address_list =
(Address = (Protocol = TCP) (host = 192.168.3.1) (Port = 1521 ))
)
(CONNECT_DATA =
(SID = pubs)
)
(HS = OK)
)

Save

6 now that the transparent gateway configuration is complete, you can test the connection at the command line prompt: tnsping pubs

If the test is OK, the test is completed. If the test times out, check the ora files in detail and make sure that port 1521 is enabled on the SQL Server server to avoid being intercepted by the firewall.

You can create a database link as follows:

SQL> Create public database link pubs connect to sa identified by PWD using 'pubs ';

SQL> select * from stores @ pubs;

SQL> select "column1" from Table1 @ pubs;