anchor.diff:  * `_exact-numeric-type_` is:
   +
   ```
  -   NUMERIC [(_precision_ [,_scale_])] [SIGNED|UNSIGNED]
  +   NUMERIC [(precision [,scale])] [SIGNED|UNSIGNED]
   | TINYINT [SIGNED|UNSIGNED]
   | SMALLINT [SIGNED|UNSIGNED]
   | INT[EGER] [SIGNED|UNSIGNED]
   | LARGEINT
  -| DEC[IMAL] [(_precision_ [,_scale_])] [SIGNED|UNSIGNED]
  +| DEC[IMAL] [(precision [,scale])] [SIGNED|UNSIGNED]
   ```
   
   * `_approximate-numeric-type_` is:
   +
   ```
  -   FLOAT [(_precision_)]
  +   FLOAT [(precision)]
   | REAL
   | DOUBLE PRECISION
   ```
  
positive.code: +
  ```
    DATE
  | TIME [(_time-precision_)]
  | TIMESTAMP [(_timestamp-precision_)]
  ```
  
  * `DATE`
  
negative.code: VARYING column is actually four bytes larger than the size required for
  an equivalent column that is not VARYING.
  
  * `VARCHAR (_length_ [_unit_]) [_char-set_] [UPSHIFT] [[NOT]CASESPECIFIC]`
  +
  specifies a column with varying-length character data. VARCHAR is
  equivalent to data type CHAR[ACTER] VARYING.
  
  * `NCHAR [(_length_)] [UPSHIFT] [[NOT]CASESPECIFIC], NATIONAL CHAR[ACTER] [(_length_)] [UPSHIFT] [[NOT]CASESPECIFIC]`
  +
  specifies a column with data in the predefined national character set(USC2).
  
  * `NCHAR VARYING [(_length_)] [UPSHIFT] [[NOT]CASESPECIFIC], NATIONAL CHAR[ACTER] VARYING (_length_) [UPSHIFT] [[NOT]CASESPECIFIC]`
  +
  specifies a column with varying-length data in the predefined national character set(USC2).
  
  [[considerations_for_character_string_data_types]]
  ==== Considerations for Character String Data Types
  