How to create TNS_ADMIN environment variable?

01. First, you have to create a directory whose name is "0_library", which is on a "C" disk.

02. Then you'll have to copy one of TNSNAMES.ORA files into that directory

03. Now it makes sense to point the TNS_ADMIN environment variable to the "c:\0_library" directory             because, if it doesn't exist or if it is empty, the whole TNS_ADMIN story doesn't make any sense

04. When necessary, maintain this TNSNAMES.ORA file; the rest of them (which are in their \network\admin           directories) should be renamed into, for example, TNSNAMES_OLD.ORA.

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