Oracle - export results to excel with headers/columns more than 30 characters
No, it isn't possible to do this. As stated in the docs, the maximum length of object name (tables, columns, triggers, packages, etc.) is 30 bytes:
http://docs.oracle.com/database/121/SQLRF/sql_elements008.htm#SQLRF51129
The only exceptions are database names (8 byte limit) and database links (128 bytes).
As of Oracle Database 12.2, the maximum length of names increased to 128 bytes (provided compatible is set to 12.2 or higher). Database names are still limited to 8 bytes. And the names of disk groups, pluggable databases (PDBs), rollback segments, tablespaces, and tablespace sets are limited to 30 bytes.
According to AllRoundAutomations it isn't possible
On Oracle 12.1 this is not possible. On Oracle 12.2 and later you can use long identifiers.