Shouldnt you be using the Oracle Driver instead of the Microsoft ODBC driver Microsofts driver will require the SQLNet drivers which come with your full client. Here is how to create a database link from Oracle Database 11g to Microsoft SQL Server. First, configure the Microsoft ODBC Driver 11 for SQL Server. SAP Crystal Reports, developer version for Microsoft Visual Studio Supported Platforms SAP COMMUNITY NETWORK SDN sdn. BPX bpx. sap. com BOC boc. Oracle SQL Developer 4 and the Oracle Client. You dont need to have an Oracle Client installed on your machine to use Oracle SQL Developer. Everything you need to connect to Oracle Database is provided by the JDBC driver included with the download. So you can be up and running in usually less than 5 minutes. But if you DO happen to have a Client on your machine, youll be happier. If youre too lazy to go read the above post, here it is in a nutshell JDBC doesnt do everything that OCI can. OCI does a better job at reliably cancelling queries. OCI has better support for advanced data types including XMLSo, if youre on board with the idea of connecting up your Oracle Client with SQL Developer, lets talk about how to get that going. Prior to version 4, you would tell SQL Developer to use the OCIThick driver by the way, OCI stands for Oracle Client Interface. Yes or No, basically. OracleDriverandKerberos/odbc.png' alt='Install Odbc Drivers For Oracle 12C' title='Install Odbc Drivers For Oracle 12C' />The problem here is that many of you have more than one Client on your machine. So not being able to explicitly tell SQL Developer WHICH client to use was problematic. So in version 4, weve enhanced the preferences to allow you to tell us exactly what client to use. Now you can say what client you want us to use. Note the actual PATH I have here is Instant Client file C Program FilesOracle1. Instant. Clientinstantclient1. Metal Hammer Magazine. You can put the Instant Client anywhere on your machine, but we need the directory location of where we can find these files We get really picky, so you need to get this RIGHT. The Preferences. Use Oracle Client. This tells SQL Developer WHERE your client is. It will then use this location to attempt to load the OCI stuff when doing things like a Password Reset on an expired connection. It wont cause SQL Developer to use the OCIThick driver for connections though. Use OCI Thick Driver. This DOES tell SQL Developer to make OCIThick connections to your Oracle database. It will use the client specified in the previous preference. SQL Developer will attempt to confirm that your Client is available once you click OK. If its an Instant Client, it will check the OS Path to make sure its there. Note we can only look at the first item in the path, so you may get a false positive, in which case you can ignore by clicking Yes here. This just says, we tried to find this in the Path and failed you can ignore IF you can connect. How Do I Know if I Did it RightYou can check two things. One on a disconnected connection, right click. If you see Reset Password available, youre golden. Two, you can open Help About and check the properties a la SQL Developer IS able to load the drivers, you win One Last Thing. SQL Developer 4 ships with an 1. JDBC driver. That means youll want at least an 1. Client for this to be compatible with SQL Developer. At some point well ship with a 1. But well worry about that later.