HP 3000 Manuals

KSAM/3000 Reference Manual

KEYSEQ 

Verifies sequence of key values in KSAM file.

 {KEYSEQ}
>{KS    }[filereference] [;SEQ=keysequence] [;OFFLINE] [;NOLIST]

This command compares all the key values in a particular key (primary or
alternate) to determine whether they are in ascending sequence.  If any
values are out of sequence, a list of numbers identifying such values is
displayed, unless NOLIST is specified.  In any case, the number of
outquence values is returned.  Note that if key values are out of
sequence, the key file is damaged and the KSAM file must be reloaded.

The abbreviation KS may be used instead of the keyword KEYSEQ.

PARAMETERS 

filereference    Actual file designator identifying the KSAM file whose
                 key values are to be verified.  Either the data file
                 name or the key file name can be used to identify a KSAM
                 file.  Also, a back reference to a file named in an MPE
                 :FILE command may be used.

                 (Optional parameter if no parameters are specified.)

                 Default:  If omitted, the last file referenced is 
                 assumed.

SEQ=             Identifies particular key whose key values are to be
keysequence 
                 checked.  Keys are numbered from 1.  The first key
                 (SEQ=1) is always the primary key; subsequent keys are
                 alternate keys numbered in the order they appear in the
                 record, such that the first alternate key in the record
                 is SEQ=2, the second alternate key is SEQ=3, and so
                 forth.

                 (Optional parameter.)

                 Default:  If omitted, the primary key is assumed. 

OFFLINE          Directs list of out-of-sequence keys to the line
                 printer.  An MPE :FILE command may be used to indicate a
                 different output device than the line printer, or a
                 particular line printer.

                 (Optional parameter.)

                 Default:  If omitted, the list of out-of-sequence keys 
                 is displayed at user's terminal.

NOLIST           Suppresses display of the particular key numbers whose
                 values are out of sequence.  A count of the
                 out-of-sequence values is displayed even if NOLIST is
                 specified.

                 (Optional parameter.)

                 Default:  If omitted, list of key numbers for 
                 out-of-sequence key ualues is displayed. 

VERIFY KEY SEQUENCE 

If you suspect that your key file has out of order key values in any key,
you can run KEYSEQ. If any key values are not in ascending sequence, the
key numbers associated with those key values are displayed.  Note that
the number of a key value refers to its position in the key file.  For
example, if the third, fourth, and fifth key values of a particular key
are out of sequence, the numbers 3, 4, and 5 are displayed.

If the list of out-of-sequence key numbers is long, you can terminate it
by holding down the CNTL key while typing Y (CNTL/Y). The total number of
out-of-sequence key values will be displayed even if you terminate the
list with CNTL/Y or suppress it altogether with NOLIST.

Consider the following partiallist of key values in the primary key of
the KSAM file MYFILE:


If you run KSAMUTIL and use the KEYSEQ command, as shown below, you can
determine which keys are out of order:

     :RUN KSAMUTIL.PUB.SYS 
     >KEYSEQ MYFILE ;SEQ=1<----------- test primary key sequence 

KEYSEQ displays the following:

     KEY VALUE # (FOR VALUE OUT OF SEQUENCE)
     3 ------ key number of keys with out-of-sequence values 
     4 -------|
     TOTAL # OF KEY VALUES READ       30
     # OF KEY VALUES OUT OF KEY SEQUENCE ORDER            2
     KEY FILE STRUCTURE DAMAGED, KSAM FILE HAS TO BE RELOADED

Regardless of the number of key values that are out of sequence, you
should reload the KSAM file to restore its integrity.

Consider a second example.  Suppose MYFILE has two alternate keys, one
starting in location 11 (11th character of record) and another starting
in location 33.  To verify the sequence of key values in the second
alternate key, execute KEYSEQ as follows:

          >KS MYFILE ;SEQ=3 ;NOLIST <----- suppress list of key numbers 
                          |
                          |------ second alternate key 

          TOTAL # OF KEY VALUES READ 30
          #OF KEY VALUES OUT OF KEY SEQUENCE ORDER 0 <--- key values in sequence 

In this case all the key values were in correct sequence.  Unless other
keys in this file have values that are out of sequence, you need not
reload the file.

Note that NOLIST was specified.  In general this is good practice.  If
any key values are not in sequence, the file should be reloaded, so it is
seldom important to know which keys are out of sequence.

MPE/iX 5.0 Documentation