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Changing Record Lengths in IQL3 Page 1
1. Standard (Field Image or Field Test) versions of IQL3 are
distributed with generous record lengths for user data files.
If you do not have files with records this long, IQL uses more
core than necessary. You can cut down on (or enlarge) these
record lengths with no impact on the output of IQL, and the
shorter the record lengths, the faster IQL will run.
2. The standard compiled-in record lengths on distributed versions
are, at the time of writing:
Primary ASCII sequential file: 3410 characters
Primary SIXBIT sequential file: 4092 characters
Primary ASCII ISAM file: 3410 characters
x 10 blocking factor
Primary SIXBIT ISAM file: 4092 characters
x 10 blocking factor
Secondary ASCII sequential file: 3410 characters
(also tertiary)
Secondary SIXBIT sequential file: 4092 characters
(also tertiary)
Secondary ASCII ISAM file: 3410 characters
(and tertiary) x 10 blocking factor
Secondary SIXBIT ISAM file: 4092 characters
(and tertiary) x 10 blocking factor
3. Normally secondary and tertiary files are used for lookup under
control of the primary file. They are usually quite a bit
shorter than the primary file, which is often a long record
length master file.
4. We therefore suggest consideration of the following procedure:
1. Canvass your users to see what the longest record lengths
they expect to present to IQL. Break expected file usage
into one of the categories shown above.
2. Edit the IQL sources as described in the next paragraph and
regenerate the system with the new record lengths.
3. If you are using DBMS, leave the primary SIXBIT file record
length (the file is named INF1SD6) sufficiently long to
hold the concatenated records from the database. IQL
abutts the database records end-to-end in this buffer,
thereby requiring that it be moderately large. In certain
installations using DBMS, it may even be the case that the
default record buffer size is too small for very large DBMS
schemas. In such cases, it is permissable to increase the
primary buffer size as necessary to accomodate such
schemas.
Changing Record Lengths in IQL3 Page 2
4. If you choose to change the ISAM data file blocking factors
from 10, you should also change the value of the item
MAX-BLKFACT in IQL.CBL, which is used to test for and
generate a warning message in case someone tries to define
a dictionary with a bloking factor too large. It is at
line sequence number 002715, which is at the beginning of
the WORKING-STORAGE section.
5. There is a problem in IQL that is inherent to its use of COBOL
and which will go away with COBOL V13:
1. COBOL, at RESET time, checks the parameters of the
compiled-in ISAM files against named files that it requires
to be found on DSK:. This is the reason the dummy files
ISAMF6.IDX and ISAMF7.IDX are required.
2. At OPEN time COBOL complains if the parameters of the file
actually opened (IQL changes the files' names and
parameters such as record length, blocking factor, key
location, key length, etc. after reset time and before
OPEN time).
3. As distributed, COBOL V12 required that the parameters on
the opened file match exactly those compiled-in. PCO #535
changed this so that COBOL V12 requires that the record
length of the opened file be not greater than the
copiled-in record length, and that the blocking factor of
the opened file be not greater than that of the compiled-in
file. This means that in setting up the new ISAM file
parameters in IQL you should independently set the record
length to the maximum record length you expect for any ISAM
file, and the blocking factor independently to the maximum
blocking factor you expect in any such ISAM file. The
alternative is to block down the actual ISAM data files for
IQL usage.
Changing Record Lengths in IQL3 Page 3
6. The following lines in the modules shown are those to change
for record lengths:
Module IQE:
Primary sequential SIXBIT file:
002120 01 INF1SD6-REC PIC X(3410).
Primary sequential ASCII file:
002260 01 INF1SD7-REC PIC X(3410).
Secondary and Tertiary sequential SIXBIT files:
002400 01 INF2SD6-REC PIC X(3410).
002680 01 INF3SD6-REC PIC X(3410).
Secondary and Tertiary sequential ASCII files:
002540 01 INF2SD7-REC PIC X(3410).
002820 01 INF3SD7-REC PIC X(3410).
Primary SIXBIT ISAM file:
003400 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
003440 01 INF1ISAM6-REC.
003460 02 INF1ISAM6-RECKEY PIC X(30).
003480 02 FILLER PIC X(4062).
Primary ASCII ISAM file:
003580 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
003620 01 INF1ISAM7-REC.
003640 02 INF1ISAM7-RECKEY PIC X(30).
003660 02 FILLER PIC X(4062).
Secondary and Tertiary SIXBIT ISAM files:
003760 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
003800 01 INF3ISAM6-REC.
003820 02 INF3ISAM6-RECKEY PIC X(30).
003840 02 FILLER PIC X(4062).
004120 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
004160 01 INF3ISAM6-REC.
004180 02 INF3ISAM6-RECKEY PIC X(30).
004200 02 FILLER PIC X(4062).
Secondary and Tertiary ASCII ISAM files:
003940 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
003980 01 INF2ISAM7-REC.
004000 02 INF2ISAM7-RECKEY PIC X(30).
004020 02 FILLER PIC X(3380).
Changing Record Lengths in IQL3 Page 4
004300 LABEL RECORDS ARE STANDARD
BLOCK CONTAINS 10 RECORDS
004340 01 INF3ISAM7-REC.
004360 02 INF3ISAM7-RECKEY PIC X(30).
004380 02 FILLER PIC X(3380).
Changing Record Lengths in IQL3 Page 5
Module IQU
001420 FD QIFLE7
001440 VALUE OF IDENTIFICATION IS QIFLE7-ID
001460 LABEL RECORD IS STANDARD
001480 BLOCK CONTAINS 0 RECORDS
001500 DATA RECORD IS QIFLE7-REC.
001520 01 QIFLE7-REC USAGE IS DISPLAY-7.
001540 02 FILLER PIC X(3410).
001560
001580 FD QIFLE6
001600 VALUE OF IDENTIFICATION IS QIFLE6-ID
001620 LABEL RECORD IS STANDARD
001640 BLOCK CONTAINS 0 RECORDS
001660 DATA RECORD IS QIFLE6-REC.
001680 01 QIFLE6-REC USAGE IS DISPLAY-6.
001700 02 MAIN-REC.
001720 04 MAIN-REC72 PIC X(72).
001740 04 FILLER PIC X(4020).
001760
001780 FD QOFLE7
001800 VALUE OF IDENTIFICATION IS QOFLE7-ID
001820 LABEL RECORD IS STANDARD
001840 BLOCK CONTAINS 0 RECORDS
001860 DATA RECORD IS QOFLE7-REC.
001880 01 QOFLE7-REC USAGE IS DISPLAY-7.
001900 02 FILLER PIC X(3410).
001920
001940 FD QOFLE6
001960 VALUE OF IDENTIFICATION IS QOFLE6-ID
001980 LABEL RECORD IS STANDARD
002000 BLOCK CONTAINS 0 RECORDS
002020 DATA RECORD IS QOFLE6-REC.
002040 01 QOFLE6-REC USAGE IS DISPLAY-6.
002060 02 FILLER PIC X(4092).
002280 FD QISAM6
002300 VALUE OF IDENTIFICATION IS QIFLE6-ID
002320 LABEL RECORDS ARE STANDARD
002340 BLOCK CONTAINS 10 RECORDS
002360 DATA RECORD IS QISAM6-REC.
002370* *NOTE THAT BOTH RECORD AND KEY BELOW -MUST- BE WORD-ALIGNED
002380 01 QISAM6-REC DISPLAY-6.
002390 02 QISAM6-RECKEY PIC X(30).
002400 02 FILLER PIC X(4062).
002404
002440 FD QISAM7
002460 VALUE OF IDENTIFICATION IS QIFLE7-ID
002480 LABEL RECORDS ARE STANDARD
002500 BLOCK CONTAINS 10 RECORDS
002520 DATA RECORD IS QISAM7-REC.
002530* *NOTE THAT BOTH RECORD AND KEY BELOW -MUST- BE WORD-ALIGNED
002540 01 QISAM7-REC USAGE IS DISPLAY-7.
002550 02 QISAM7-RECKEY PIC X(30).
Changing Record Lengths in IQL3 Page 6
002560 02 FILLER PIC X(3380).