OCIEnvCreate failed to create environment handle after installing oracle_fdw

You have to set the environment variables LD_LIBRARY_PATH and ORACLE_HOME for the user postgresql. Then you have to set the service to conncet in the file tnsname.ora, the you have to create a foreign server with dbserver=Service (you should have defined the Service in the file `tnsname.ora

I send you my files configurations in Debian:

I added to /etc/profile (apply for all system user) but you can use .bashrc or another for only one user.

Oracle

ORACLE_HOME=/usr/lib/oracle/xe/app/oracle/product/10.2.0/client
export ORACLE_HOME
LD_LIBRARY_PATH=$ORACLE_HOME/lib:$ORACLE_HOME:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH
PATH=$PATH:$ORACLE_HOME/bin
export TNS_ADMIN=$ORACLE_HOME/network/admin

Postgresql Path

PATH=$PATH:/usr/local/pgsql/bin
export PATH
MANPATH=$MANPATH:/usr/local/pgsql/man
export MANPATH

The variable TNS_ADMIN will be a directory where you install a tnsnames.ora

tnsnames.ora:

ORA11 =
 (DESCRIPTION = 
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
   )
 (CONNECT_DATA =
   (SERVICE_NAME = ORA11)
 )
)

Then create a foreign server for oracle_fdw with option dbserver=ORA11

I was able to install oracle_fdw, between Postgresql and Oracle. I've installed Oracle Instant client on the Linux machine.

On the Postgresql server, I've installed Oracle Client, and configured it to connect to the Oracle database. sqlplus name/password@ORCL is working on the command line.

My tnsnames.ora is:

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.148.51.2)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = ORCL)
    )
  )

I've copied tnsnames.ora to $ORACLE_HOME/network/admin/tnsnames.ora

My environment variables are:

export ORACLE_HOME=/usr/lib/oracle/11.2/client64
export TNS_ADMIN=$ORACLE_HOME/network/admin
export PATH=$ORACLE_HOME/bin:/usr/pgsql-9.1/bin/:$PATH
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH

On the postgresql init script, /etc/init.d/postgresql, I've also set the variables:

export ORACLE_HOME=/usr/lib/oracle/11.2/client64
export TNS_ADMIN=$ORACLE_HOME/network/admin

I've also changed the file /etc/ld.so.conf.d/postgresql-9.1-libs.conf

$ cat /etc/ld.so.conf.d/postgresql-9.1-libs.conf
/usr/pgsql-9.1/lib/
/usr/lib/oracle/11.2/client64/lib/

$ sudo ldconfig
$ sudo /etc/init.d/postgresql restart

To use oracle_fdw, I used:

$ psql ide

ide=# CREATE EXTENSION oracle_fdw;
ide=# CREATE SERVER medidata FOREIGN DATA WRAPPER oracle_fdw OPTIONS (dbserver '//192.148.51.2:1521/ORCL');

I already have a small table in Oracle called 'zonas'. To use 'zonas' in Postgresql, I've done:

ide=# CREATE FOREIGN TABLE zonas (
    COD_ZONA text,
    ZONA    text,
    RESPONSAVEL       numeric
    ) 
SERVER medidata
OPTIONS (table 'zonas');

ide=# select * from zonas;
 cod_zona | zona | responsavel 
----------+------+-------------
 2        | 2    |           2
 1        | 1    |           1
(2 rows)

I hope it helps.