3) Extract the two Instant Client downloads into the same directory somewhere.
4) Create your tnsnames.ora file somewhere (if you don't already have one). This file describes how to connect to one or more Oracle databases to any Oracle software on your computer, such as the Instant Client. It's widely documented on the web, like on this page. If you have a RAC and don't know much about this file (like me before this morning), then someone else probably set up the cluster. Get a tnsnames.ora entry from them and just paste it into a text file somewhere. I just put the tnsnames.ora in the same directory where I extracted the Instant Client.
5) Add/edit two environment variables. First, add the directory from 3) to your library path. In Windows, this means adding the directory to your PATH. For Linux:
Then add a TNS_ADMIN variable that points to the directory that contains tnsnames.ora (the same as the library directory if you put it with the rest of the extracted files).
6) Use JDBC to connect like normal with these settings (and a username + password, of course, if applicable):
driverClass=oracle.jdbc.driver.OracleDriver connectionUrl=jdbc:oracle:oci:@<database alias>
where <database alias> is the alias specified in tnsnames.ora. It's the left hand side of the initial assignment in a TNS entry--"FITZGERALD.SALES" in this example:
FITZGERALD.SALES = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = server1)(PORT = 1521)) (CONNECT_DATA = (SID = ORCL) ) )That's it! Section 7.4.3 of the Oracle JDBC Developer's Guide has a good rundown of different ways you can use JDBC to connect with OCI once you get it installed. I don't claim that this is the best way to do any of this. I just know it works.