question: public String indexColumnFamilyName ( ColumnDefinition info ) { return cfName + Directories . SECONDARY_INDEX_NAME_SEPARATOR + ( info . getIndexName ( ) == null ? ByteBufferUtil . bytesToHex ( info . name . bytes ) : info . getIndexName ( ) ) ; }
target:  generate a column family name for an index corresponding to the given column. This is NOT the same as the index's name! This is only used in sstable filenames and is not exposed to users.