That old $TNS_ADMIN environment variable

Somebody reminded me that I should include the $TNS_ADMIN variable to avoid unnecessary file searches (minor expense) in the Mac configuration instructions. This eliminates additional searches when running sqlplus and tnsping executables. I’ve updated that blog page with those instructions. It’s not necessary to make it work but it does avoid a read to the local and /etc directories on your Mac OS X for a tns_names.ora file before reading it from the $ORACLE_HOME/network/admin directory.