WITH S AS ( /*SELECT QUERY*/ ) SELECT /*COLUMN NAMES*/ , LENGTH( FLOOR ( /*DECIMAL COLUMN*/ )) + NVL(LENGTH( RTRIM (SUBSTR(CN,INSTR(CN, '.' ) + 1 ), '0' )), 0 ) NUMBER_OF_DEGITS, NVL(LENGTH( RTRIM (SUBSTR(CN,INSTR(CN, '.' ) + 1 ), '0' )), 0 ) NUMBER_OF_DECIMALS FROM ( SELECT /*COLUMN NAMES*/ , TO_CHAR( /*DECIMAL COLUMN*/ , 'FM99999999999999999D99999999999999999' , 'NLS_NUMERIC_CHARACTERS = ''. ''' ) CN FROM S );