With instant client you can run into problems if you set ORACLE_HOME so don't. Just set LD_LIBRARY_PATH to the path to where you installed instant client. e.g., I installed instant client in /home/martin/instantclient_11_1 (which is a dir created by unzipping sdk, sqlplus and basic zip files). The I set LD_LIBRARY_PATH to /home/martin/instantclient_11_1 and export it:

export LD_LIBRARY_PATH=/home/martin/instantclient_11_1:$LD_LIBRARY_PAT
+H
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NOTE you really should install the sqlplus package too because a) you can check you can access oracle first before playing with perl and b) DBD::Oracle uses sqlplus (if it exists) to work out your oracle version.

So /home/martin/instantclient_11_1 contains:

adrci         libclntsh.so       libociei.so      ojdbc5.jar  SQLPLUS_
+README
BASIC_README  libclntsh.so.11.1  libocijdbc11.so  ojdbc6.jar
genezi        libnnz11.so        libsqlplusic.so  sdk
glogin.sql    libocci.so.11.1    libsqlplus.so    sqlplus
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and the first part of running Makefile.PL should show something like:

~/svn/dbd-oracle/trunk$ perl Makefile.PL
Using DBI 1.611 (for perl 5.010000 on i486-linux-gnu-thread-multi) ins
+talled in /usr/local/lib/perl/5.10.0/auto/DBI/

Configuring DBD::Oracle for perl 5.010000 on linux (i486-linux-gnu-thr
+ead-multi)

Remember to actually *READ* the README file! Especially if you have an
+y problems.

Trying to find an ORACLE_HOME
Your LD_LIBRARY_PATH env var is set to '/home/martin/instantclient_11_
+1/'
Found /home/martin/instantclient_11_1/

WARNING: Setting ORACLE_HOME env var to /home/martin/instantclient_11_
+1/ for you.
WARNING: If these tests fail you may have to set ORACLE_HOME yourself!
Installing on a linux, Ver#2.6
Using Oracle in /home/martin/instantclient_11_1/
DEFINE _SQLPLUS_RELEASE = "1101000600" (CHAR)
Oracle version 11.1.0.6 (11.1)
Looks like an Instant Client installation, okay
Your LD_LIBRARY_PATH env var is set to '/home/martin/instantclient_11_
+1/'
Oracle sysliblist: 
Found header files in /home/martin/instantclient_11_1//sdk/include.

Checking for functioning wait.ph
.
.
.
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