Upgrading the Python Oracle Client

This is a follow up to one of my previous postings: Python and the Oracle Client. The main databases here are being upgraded to Oracle 12 and I’ve taken the opportunity to update the client used by my Python scripts, also its good practice to install new clients when old versions go out of support.

Current Setup

The system I am upgrading here has the following configuration, but this should work with any RPM based distribution, such as CentOS and SUSE :

  • Red Hat Enterprise Linux Server release 6.6 (Santiago)
  • Python 2.6.6
  • python connector: cx_Oracle – 5.1.2
  • oracle-instantclient11.2-basic-11.2.0.4.0-1.x86_64
  • oracle-instantclient11.2-devel-11.2.0.4.0-1.x86_64

To find the versions of your currently installed software:
$ python
Python 2.6.6 (r266:84292, Nov 21 2013, 10:50:32)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import cx_Oracle
>>> print cx_Oracle.version
5.1.2

and the Oracle client:
$ rpm -qa | grep oracle
oracle-instantclient11.2-basic-11.2.0.4.0-1.x86_64
oracle-instantclient11.2-devel-11.2.0.4.0-1.x86_64

Preparing

If you have the old versions installed you will need to do some tidying up by removing the client and python connector, version 11 of the client despite being RPM packaged had some non-standard elements. Use rpm to delete the old version of instant client, remove devel first:
$ sudo su
# rpm -ev oracle-instantclient11.2-devel-11.2.0.4.0-1.x86_64
# rpm -ev oracle-instantclient11.2-basic-11.2.0.4.0-1.x86_64

you may also need to remove the library reference from a previous installation:
# rm /etc/ld.so.conf.d/oracle.conf
# ldconfig

to remove the Python oracle connector, there are two methods. Manually, by finding the previously installed package deleting the files and editing the package list:
# find / -name cx_Oracle.py -print
/usr/lib/python2.6/site-packages/cx_Oracle-5.1.2-py2.6-linux-x86_64.egg/cx_Oracle.py
# cd /usr/lib/python2.6/site-packages
# rm -rf cx_Oracle-5.1.2-py2.6-linux-x86_64.egg

now edit the easy-install.pth file
# nano /usr/lib/python2.6/site-packages/easy-install.pth
and remove the line:
./cx_Oracle-5.1.2-py2.6-linux-x86_64.egg

Or do it the easy way, if you have pip installed:
# sudo pip uninstall cx_Oracle
easy_install does not have an uninstall option.

Installing

Download and install version 12 of the Instant Client and SDK (devel), these can be gotten from: http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html For Linux choose the correct flavour for your installed operating system: x86 or x86-64 for 64bit operating systems, you will need to register on the site gain access the files.
# rpm -i oracle-instantclient12.1-basic-12.1.0.2.0-1.x86_64.rpm
# rpm -i oracle-instantclient12.1-devel-12.1.0.2.0-1.x86_64.rpm

Now to install the python connector:
# easy_install cx-Oracle
or, the recommended method:
# pip install cx-Oracle
Installation for the version 12 client is much more straight forward than that for version 11.

Testing

A quick test to ensure that the expected versions appear, and that you can connect to the database.
Python 2.6.6 (r266:84292, Nov 21 2013, 10:50:32)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import cx_Oracle
>>> cx_Oracle.version
'5.2'
>>> oraConn = "<USERNAME>/<PASSWORD>@<DATABASE HOST>:<DATABASE PORT>/<SERVICE>"
>>> ocDB = cx_Oracle.connect(oraConn)
>>> ocDB.version
'12.1.0.2.0'

Sources

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