Usage Scenario: When you need to access data from an Oracle database on another SQL Server database, Oracle provides a tool: gateways. With this tool, you can create dblink to connect to SQL Server or a different company's database----depending on your installation options.
After installing gateways, use the following 2 ways to create Dblink
Mode A:
Create DATABASE link Bslink
Connect to ' username ' identified by "password"
Using ' (DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP) (HOST = Remoteip) (PORT = 1433))
(Connect_data = (
SID = SQL Server database name) (Hs=ok)) '
This approach is not required to configure Initdg4msql.ora and TNSNames.
Mode B:
1. In the $oracle_home/dg4msql/admin/initdg4msql----This step can be omitted using mode a instead
Configure Initdg4msql.ora to my example, as follows:
******************************
# This was a customized agent init file that contains the HS parameters
# that is needed for the Database Gateway for Microsoft SQL Server
#
# HS init parameters
#
Hs_fds_connect_info=[192.168.101.4]//bsdata----Only need to modify this ip//database name
Hs_fds_trace_level=off
Hs_fds_recovery_account=recover
Hs_fds_recovery_pwd=recover
2. Configure Listener.ora under the Network\admin directory in the Oracle home directory. In my case, the following:
******************************
# LISTENER. ORA Network Configuration File:c:\oracle\ora92\network\admin\listener.ora
# Generated by Oracle configuration tools.
LISTENER =----here LISTENER named LISTENER
(Description_list =
(DESCRIPTION =
(Address_list =
(ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.1.180) (PORT = 1521))
)
)
)
Sid_list_listener =-----here Sid_list_lintener name Ibid. LISTENER
(Sid_list =
(Sid_desc =
(Sid_name = dg4msql)
(Oracle_home = D:\app\oracle\product\11.2.0\dbhome_1)
program = dg4msql)----Here program corresponds to Dg4msql in TNSNames
)
)
3. Configure the Tnsnames.ora in the Network\admin directory under the Oracle home directory, in my case, as follows:
******************************
Dg4msql =---Ibid correspondence
(description=
(Address= (PROTOCOL=TCP) (Host=localhost) (port=1521))
(Connect_data= (Sid=dg4msql))
(Hs=ok)
)
******************************
Oracle uses Dblink to connect to SQL Server