Oracle Instant Client on OS X Revision as of Friday, 4 June 2021 at 03:52 UTC

Head to the download page (login required since Oracle is terrible) and download these files

instantclient-basic-macos.x64-12.2.0.1.0-2.zip
instantclient-sdk-macos.x64-12.2.0.1.0-2.zip
instantclient-sqlplus-macos.x64-12.2.0.1.0-2.zip

Make sure that you get the 64-bit versions (for 64-bit Pythons), else you’ll see something like this at import

ImportError: dlopen(/Users/nikhil/.pyenv/versions/manifold-api/lib/python2.7/site-packages/cx_Oracle.so, 2): Symbol not found: _OCIAttrGet  
  Referenced from: /Users/nikhil/.pyenv/versions/manifold-api/lib/python2.7/site-packages/cx_Oracle.so  
  Expected in: flat namespace

Easy Way

Uses Homebrew. Copy the files downloaded above to /Users/$USER/Library/Caches/Homebrew. Then run these commands

brew install InstantClientTap/instantclient/instantclient-basic
brew install InstantClientTap/instantclient/instantclient-sdk
brew install InstantClientTap/instantclient/instantclient-sqlplus

Done! To set up tnsnames.ora,

mkdir -p /usr/local/opt/instantclient-basic/network/admin
touch /usr/local/opt/instantclient-basic/network/admin/tnsnames.ora

and add stuff to that file.

Laborious Way

Extract the downloaded files at the command line. You’ll get a folder called instantclient_12_2
Move it to /usr/local

sudo mkdir /usr/local/oracle  
sudo mv instantclient_12_2 /usr/local/oracle/instantclient  
sudo chown user:group /usr/local/oracle

Set some environment variables

export ORACLE_HOME=/usr/local/oracle/instantclient  
export OCI_HOME=$ORACLE_HOME  
export OCI_LIB_DIR=$OCI_HOME  
export OCI_INCLUDE_DIR=$OCI_HOME/sdk/include  
export NLS_LANG=AMERICAN_AMERICA.UTF8  
export DYLD_LIBRARY_PATH=$OCI_LIB_DIR

Last steps

cd $OCI_LIB_DIR  
ln -s libclntsh.dylib.11.1 libclntsh.dylib  
ln -s libocci.dylib.11.1 libocci.dylib