Create a linked server for Oracle in 64-bit SQL Server

First, install the driver
If you are using a 32-bit win2003 operating system, there will be a system-brought Microsoft OLE DB Provider for Oracle driver, so no additional preparation is required, but if you are using a 64-bit system, this driver is not, and Microsoft does not provide the 64-bit version of this driver, so only Oracle Provider for OLE DB is available at this time.
Installing a complete ORACLE11GR2 program is also an effective method, but this 64-bit version of the installation package has 2 multi-g, quite large, if only to establish a linked server, there is no need to install such a monster. In fact, we only need to download the ODAC compressed package on the Oracle official website.
Http://www.oracle.com/technetwork/topics/dotnet/utilsoft-086879.html
I downloaded ODAC 11.2 Release 4 and Oracle Developer Tools for Visual Studio (11.2.0.3.0)

Http://jingyan.baidu.com/album/e4511cf336ce872b845eafd4.html

Http://jingyan.baidu.com/article/27fa7326e0879246f8271fc2.html

Http://www.cnblogs.com/gisdream/archive/2012/05/19/2508993.html

64bit System installation ODAC Be sure to install the 32bit version (that is, the Oracle 11g Client is 32bit), otherwise ODAC will not be available.

Create a linked server for Oracle in 64-bit SQL Server