HP 3000 Manuals HP 3000 Manuals
END-OF-FILE ON KSAM FILES
The first step in understanding what KEYINFO does and why it is needed,
is to understand how KSAM end-of-files are set and maintained. Each of
the two files that comprise a KSAM file (the data Ele and the key file)
has two end-of-file marks: an MPE end-of-file and a KSAM internal
end-of-file. Thus, there are four end-of-files to consider. The main
characteristics of each of these end-of-files are shown below:
DATA FILE
MPE End-Of-File:
* Number of records in fixed-length record file (or number of blocks in
variable-length record file).
* Stored in system file label of data file.
* Recorded on disc when file is closed (or when an SPL procedure calls
FCONTROL with control code 6) or when a new extent is allocated.
* Used by FCOPY with NOKSAM option (KSAM file is treated as an MPE
file).
* Displayed by LISTF,2:
LISTF DATAFIL,2
ACCOUNT= MORRIS GROUP= JOAN
FILENAME CODE ------------LOGICAL RECORD----------- ----SPACE----
SIZE TYP EOF LIMIT R/B SECTORS #X MX
DATAFIL KSAM 38B FA 20 20 1 23 8 8
^
|---- MPE end-of-file for data file
KSAM End-of-File:
* Address of next available logical record in the data file.
* Stored in control block of key file.
* Recorded on disc when file is unlocked or closed (or when an SPL
procedure calls FCONTROL with control code 2 or 6).
* Used by FCOPY when file is opened as a KSAM file (KEY-option)
* Displayed by VERIFY command (option 1) of KSAMUTIL:
:RUN KSAMUTIL.PUB.SYS
HP32208A.2.3 MON, APR 23, 1979, 1:11 PM KSAMUTIL VERSION:A.2.0
VERIFY DATAFIL
WHICH (1=FILE INFO, 2=KSAM PARAMETERS, 3=KSAM CONTROL, 4=ALL,)?1
DATAFIL.JOAN.MOPRIS CREATOR=JOAN
FOPTIONS(004005)=KSAM, :FILE, NOCCTL, F, FILENAME, ASCII, PERM
AOPTIONS(000400)=DEFAULT, NOBUF, DEFAULT, NO FLOCK, NO MR, IN
RECSIZE:SUB:TYP:LDNUM:DRT:UN.: CODE:LOGICAL PTR: END OF FILE:FILE LIMIT
-38: 3: 0: 3: 5: 0: 0: 0: 20: 20
|
KSAM end-of-file for data file--------------------
LOG. COUNT:PHYS. COUNT:BLK SZ:EXT SZ:NR EXT: LABELS:LDN : DISCARD:
1: 1: -38: 3: 8: 1: 3:00000010135:
Since this is a file that closed successfully, the two end-of-files
coincide.
KEY FILE
MPE End-of-File:
* File limit - Number of records (sectors) allocated to file at time of
creation
* Stored in system file label.
* Displayed by LISTF,2:
:LISTF KEYFIL,2
ACCOUNT= MORRIS GROUP= JOAN
FILENAME CODE ------------LOGICAL RECORD----------- ----SPACE----
SIZE TYP EOF LIMIT R/B SECTORS #X MX
KEYFIL KSAMK 128W FB 50 50 1 30 5 8
|
|
MPE end-of-file on key file
(set to file limit)
KSAM End-of-File
* Address of 1st record in next available key block.
* Stored in Control Block of key file.
* Recorded on disc when file is unlocked or closed (or when SPL
procedure calls FCONTROL with control codes 2 or 6).
* Used by FCOPY and KSAM procedures.
* Displayed by VERIFY command, option 3, of KSAMUTIL:
WHICH (1=FILE INTO, 2=KSAM PARAMETERS, 3=KSAM CONTROL, 4=ALL)?3
DATA FILE = DATAFIL VERSION= A.2.1
KEY CREATED=292/'78 10:19: 7.4 KEY ACCESS= 113/'79 13:11:45.8
KEY CHANGED= 93/'79 14:18: 7.6 COUNT START=292/'78 10:19:53.6
DATA RECS = 20 DATA BLOCKS= 19 END BLK WDS= 19
DATA BLK SZ= 19 DATA REC SZ= 38 AZCESSORS= 0
FOPEN 2 FREAD 0 FCLOSE 2
FREADDIR 0 FREADC 0 FREADBYKEY 0
FREMOVE 0 FSPACE 57 FFINDBYKEY 0
FGETINFO 3 FGETKEYINFO 1 FREADLABEL 0
FWRITELABEL 0 FCHECK 0 FFINDN 3
FWRITE 20 FUPDATE 0 FPOINT 0
FLOCK 0 FUNLOCK 0 FCONTRDL 0
FSETMODE 0
KEYBLK READ 7 KEYBLK WROTE 0 KEYBLK SPLIT 0
KEY FILE EOF 26 FREE KEY HD 0 SYSTEM FAILURE 0
|
KSAM internal end-of-file on key file
MIN PRIME 11 MAX PRIME 5 RESET DATE 3/'79
DATA FIXED TRUE DATA B/F 1 TOTAL KEYS 3
FIRST RECNUM 0 MIN RECSIZE 38
Since the MPE end-of-file is set to the file limit and the KSAM internal
end-of-file to the next available key block, these values never coincide
until the key file is full.