What is the minimum client footprint required to connect C# to an Oracle database?


I have successfully connected to an Oracle database (10g) from C# (Visual Studio 2008) by downloading and installing the client administration tools and Visual Studio 2008 on my laptop.

The installation footprint for Oracle Client tools was over 200Mb, and quite long winded.

Does anyone know what the minimum workable footprint is? I am hoping that it's a single DLL and a register command, but I have the feeling I need to install an oracle home, and set various environment variables.

I am using Oracle.DataAccess in my code.

9/16/2008 9:11:44 AM

Accepted Answer

You need an Oracle Client to connect to an Oracle database. The easiest way is to install the Oracle Data Access Components.

To minimize the footprint, I suggest the following :

  • Use the Microsoft provider for Oracle (System.Data.OracleClient), which ships with the framework.
  • Download the Oracle Instant Client Package - Basic Lite : this is a zip file with (almost) the bare minimum. I recommend version, which is much smaller than version
  • Unzip the following files in a specific folder :
    • v10 :
      • oci.dll
      • orannzsbb10.dll
      • oraociicus10.dll
    • v11 :
      • oci.dll
      • orannzsbb11.dll
      • oraociei11.dll
  • On a x86 platform, add the CRT DLL for Visual Studio 2003 (msvcr71.dll) to this folder, as Oracle guys forgot to read this...
  • Add this folder to the PATH environment variable.
  • Use the Easy Connect Naming method in your application to get rid of the infamous TNSNAMES.ORA configuration file. It looks like this : sales-server:1521/sales.us.acme.com.

This amounts to about 19Mb (v10).

If you do not care about sharing this folder between several applications, an alternative would be to ship the above mentioned DLLs along with your application binaries, and skip the PATH setting step.

If you absolutely need to use the Oracle provider (Oracle.DataAccess), you will need :

  • ODP .NET (the first version which allegedly works with Instant Client).
  • Instant Client, obviously.

Note that I haven't tested this latest configuration...

9/9/2009 8:51:08 AM

As of 2014, the OPD.NET, Managed Driver is the smallest footprint.

Here is a code usage comparison to the non-managed versions that previous (outdated) answers suggested: http://docs.oracle.com/cd/E51173_01/win.122/e17732/intro005.htm#ODPNT148

You will need to download these dlls and reference Oracle.ManagedDataAccess.dll in your project: Download the ODP.NET, Managed Driver Xcopy version only

Here is a typical foot print you will need to package with your release:

  1. Oracle.ManagedDataAccess.dll
  2. Oracle.ManagedDataAccessDTC.dll

all together, a whopping 6.4 MB for .Net 4.0.

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