Specifying character highkeys

Alphanumeric character keys are padded with hex ‘FF’s with only the first few characters needing to be specified.

HIGHKEYs for a Ten-Byte Alphanumeric-Character HIDAM Key

Alphanumeric HIGHKEY=	Ten-Byte HIGHKEY Padded with Hex ‘FF’s
M	M’FFFFFFFFFFFFFFFFFF’
MAC	MAC’FFFFFFFFFFFFFF’
5	5’FFFFFFFFFFFFFFFFFFF’
4999999999	499999999’FF’

If you specify all the HIGHKEY characters, DL/1 changes the last character to x’FF’. One-character root keys are invalid. A one-character key allows only 256 root keys, which is not a good candidate for a partitioned HIDAM database.

The hex ‘FF’s ensure the HIGHKEY is higher than any other key. They also ensure that it is not a valid key because the HIGHKEY cannot be used by the application program. It is reserved for DL/1 use only.

Numeric only HIGHKEYs can cause a problem because they are often right justified. With numeric character keys, all digits, with necessary leading zeroes, should be specified to generate a valid HIGHKEY.

HIGHKEYs for Ten-Byte, Numeric-Only Character HIDAM Key

Numeric HIGHKEY=	Ten-Byte HIGHKEY Padded with Hex ‘FF’s
99999	99999’FFFFFFFFFF’
0000099999	000009999’FF’
0099999000	009999900’FF’
000009	000009’FFFFFFFF’