1SELECT * FROM USER_TAB_COLS WHERE TABLE_NAME = 'my_table';
2SELECT * FROM ALL_TAB_COLS WHERE TABLE_NAME = 'my_table';
3SELECT * FROM DBA_TAB_COLS WHERE TABLE_NAME = 'my_table';
1SELECT * FROM USER_TAB_COLUMNS WHERE COLUMN_NAME = 'MY_COLUMN'; -- Connected user
2SELECT * FROM ALL_TAB_COLUMNS WHERE COLUMN_NAME = 'MY_COLUMN'; -- Other schemas
3SELECT * FROM DBA_TAB_COLUMNS WHERE COLUMN_NAME = 'MY_COLUMN'; -- All tables