遇到一个客户，有个需求，想将mssql中的数据抽取到oracle中。经过上网查找，感觉gateway这个工具可以实现，因此就搭建实验环境进行测试。首先在oracle delivery上面下载对应的安装包。
实验环境如下：
oracle数据库：
IP地址：192.168.56.100
数据库名称：orcl
数据库oracle_home：/u01/app/oracle/product/11.2.0/db_1
监听端口号：1521
gateway软件：
IP地址：192.168.56.100
gateway的home目录：/u01/app/gateway
SID名称：dg4msql
监听端口号：1523
mssql数据库：
IP地址：192.168.56.110
数据库名：MSDB
登录名：sa
密码：1qaz@WSX
上传刚才下载的软件包，将其随便解压在某个路径，在这里需要注意，我是把gateway和oracle安装在同一台服务器上，进入gateway，runInstaller开始安装：
[oracle@Abbott soft]$ cd gateways/ [oracle@Abbott gateways]$ ls doc install legacy response runInstaller stage welcome.html [oracle@Abbott gateways]$ export DISPLAY=192.168.56.1:0.0 [oracle@Abbott gateways]$ ./runInstaller
这里需要指定gateway的home名称和路径
安装for MSSQLSERVER的软件
指定要访问的数据库服务器IP地址，端口号，实例名和数据库名
在这里点击安装即可，
等安装结束后，运行如下脚本：
但是运行脚本时会有如下提示，这是因为我把gateway和oracle安装在了同一台服务器上，有些环境变量发生了冲突，直接回车，忽略：
[root@Abbott /]# /u02/app/gateway/root.sh
Running Oracle 11g root.sh script...
The following environment variables are set as:
ORACLE_OWNER= oracle
ORACLE_HOME= /u02/app/gateway
Enter the full pathname of the local bin directory: [/usr/local/bin]:
The file "dbhome" already exists in /usr/local/bin. Overwrite it? (y/n)
[n]:
The file "oraenv" already exists in /usr/local/bin. Overwrite it? (y/n)
[n]:
The file "coraenv" already exists in /usr/local/bin. Overwrite it? (y/n)
[n]:
Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root.sh script.
Now product-specific root actions will be performed.
点击OK之后会自动弹出配置监听的窗口，选择配置典型监听，然后下一步，安装完成之后推出即可：
接着查看配置文件情况，因为在安装软件的时候就指定了MSSQLSERVER的ip地址，端口号，数据库名等参数，所以这里不需要做什么修改。配置文件目录为gateway的home目录下面的$ORACLE_HOME/dg4msql/admin/initdg4msql.ora：
[oracle@Abbott admin]$ vi initdg4msql.ora # This is a customized agent init file that contains the HS parameters # that are needed for the Database Gateway for Microsoft SQL Server # # HS init parameters # HS_FDS_CONNECT_INFO=[192.168.56.110]:1433//MSDB # alternate connect format is hostname/serverinstance/databasename HS_FDS_TRACE_LEVEL=OFF HS_FDS_RECOVERY_ACCOUNT=RECOVER HS_FDS_RECOVERY_PWD=RECOVER
接着查看监听是否正常，进去之后看到没有配置静态监听，因此需要在这里添加一条静态静听（以下加黑标红部分请注意，这里的SID_NAME与配置文件的init+SID.ora中的SID要相同）。监听文件的路径为gateway_home目录下的/network/admin/listener.ora：
[oracle@Abbott admin]$ vi listener.ora
# listener.ora Network Configuration File: /u01/app/gateway/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1523))
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.100)(PORT = 1523))
)
)
ADR_BASE_LISTENER = /u01/app/oracle
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
# (GLOBAL_DBNAME = MSDB)
(PROGRAM = dg4msql)
(ORACLE_HOME = /u01/app/gateway)
(SID_NAME = dg4msql)
)
)
这里如果直接使用lsnrctl status查看监听状态，查看到的是oracle数据库的监听，因此需要export ORACLE_HOME=/u01/app/gateway，然后再使用此命令：
[oracle@Abbott admin]$ lsnrctl start LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 04-JUL-2017 09:17:09 Copyright (c) 1991, 2013, Oracle. All rights reserved. Starting /u01/app/gateway//bin/tnslsnr: please wait... TNSLSNR for Linux: Version 11.2.0.1.0 - Production System parameter file is /u01/app/gateway/network/admin/listener.ora Log messages written to /u01/app/gateway/diag/tnslsnr/Abbott/listener/alert/log.xml Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1523))) Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.100)(PORT=1523))) Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1523))) STATUS of the LISTENER ------------------------ Alias LISTENER Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production Start Date 04-JUL-2017 09:17:09 Uptime 0 days 0 hr. 0 min. 0 sec Trace Level off Security ON: Local OS Authentication SNMP OFF Listener Parameter File /u01/app/gateway/network/admin/listener.ora Listener Log File /u01/app/gateway/diag/tnslsnr/Abbott/listener/alert/log.xml Listening Endpoints Summary... (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1523))) (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.100)(PORT=1523))) Services Summary... Service "dg4msql" has 1 instance(s). Instance "dg4msql", status UNKNOWN, has 1 handler(s) for this service... The command completed successfully
监听配置成功，接着就是配置tns，注意：这里的tns需要在oracle的home/network/admin/tnsnames.ora文件中配置：
[oracle@Abbott admin]$ cat tnsnames.ora
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/11.2.0/db_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
MSDB =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST =192.168.56.100)(PORT = 1523))
(CONNECT_DATA=(SID=dg4msql))
(HS=OK)
)
配置完成后尝试tnsping：
[oracle@Abbott admin]$ tnsping MSDB TNS Ping Utility for Linux: Version 11.2.0.4.0 - Production on 04-JUL-2017 11:30:13 Copyright (c) 1997, 2013, Oracle. All rights reserved. Used parameter files: Used TNSNAMES adapter to resolve the alias Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST =192.168.56.100)(PORT = 1523)) (CONNECT_DATA=(SID=dg4msql)) (HS=OK)) OK (0 msec)
如果tnsping没有问题，接着就可以进入数据库，创建dblink，然后查询mssqlserver的数据：
SQL> create public database link aaaa connect to "sa" identified by "1qaz@WSX" using 'MSDB';
Database link created.
SQL> select * from dbo.t1@AAAA;
id
----------
1
SQL> /
id
----------
1
在表t1中再插入一行数据：
SQL> /
id
----------
1
2
遇到问题：
SQL> select 1 from dual@aaaa;
select 1 from dual@aaaa
*
ERROR at line 1:
ORA-28513: internal error in heterogeneous remote agent
ORA-02063: preceding line from AAAA
最后检查，时因为监听中的SID_NAME错误的指定成了MSSQLSERVER的数据库名称MSDB，而不是dg4msql，这里为什么要指定为dg4msql呢？因为gateway的参数文件格式为initSID.ora，而默认的SID为dg4msql，我们也没有人为改动，指定SID表明gateway具体监听的哪个数据库，而当指定了dg4msql时，它自动会寻找initdg4msql.ora这个文件，从而根据配置文件找到对应的MSSQLSERVER。