|
||||
 |
 |
|
||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
|
|||
|
||||||||||||
|
Customer Support: What's Happening in the World of FOCUS
One of the advantages of being in Customer Support is speaking with many of our customers who are creating lots of interesting applications. And that also means we can see generic problems or misunderstandings that people encounter.
With that in mind, we are launching this Customer Support column as a forum to let you know about issues that are important to the entire FOCUS community, as well as alerts, techniques, and new features.
In this column, we address the issue of the new MASTER parser. With release 7.2 of FOCUS for S/390, a new master parser became the norm. In release 7.1.1, you could SET MASTER=NEW, and we did recommend it in a few cases with VSAM groups, but it was not the default.
Now, in release 7.2, it is the default. As with other NEW settings, programmers read the documentation and assume everyone is following the rules, and so they can now enforce them. There is an entire "grammar" associated with the Master that says ACCESS goes with FILE, DESC goes with FIELD, etc. Unfortunately, although we all knew the rules, we didn't always follow them, and so we would put DESC before even the FILE declaration, and it was treated as a comment.
Other strange and wonderful variations crept into our code, and the MASTER=OLD kept on working. However, it was necessary to change it to support all the new things in masters, and so MASTER=NEW, which objects to our more "creative" variations.
Take a look at the following examples, and if in fact you have masters that are colorful, you might want to fix them before going to release 7.2 or higher. You can't stay OLD for very long.
Using Master=NewA DEFINE field in a Master File Description (MFD) had a TITLE associated with it and needed a , $ after the TITLE keyword and text associated with it. The correct syntax is
DEFINE ... ; TITLE=...,$
The problem here was that the error message indicated it did not recognize the first DEFINE reference in the TABLE request, which was not the same DEFINE in question (listed afterwards, at the end of the MFD). This is code tightening associated with SET MASTER=NEW.
With the following MFD as an example:
The result was the following message:
It works fine if you have the SEGMENT DECLARATION coded as follows:
SEGNAME=ONE,SEGTYPE= ,$
The NEW MASTER parser is requesting that an explicit SEGTYPE be supplied. If you had used S0, the ending, , $, might not have been necessary. This also is code tightening associated with SET MASTER=NEW.
A FOC1822 may be generated when there is no SEGMENT declaration at all in the MASTER. A SEGMENT declaration is now required.
A FOC1822 may also be generated when there is no dollar sign ($) coded at the end of a DEFINE field in the MFD, after the appropriate semi-colon. Since a MFD is a comma-delimited file, the dollar sign ($) is required. If there is no TITLE, as in our first example, the dollar sign ($) should be coded directly after the semi-colon (;) for the DEFINE field in question.
A FOC1822 may also appear when the first non-comment line in a MFD is not FILE=.
Examples:
(5) A FOC336 message may occur ( CHECK FILE or TABLE request) using SET MASTER=NEW.
(FOC336) THE SUM OF ALL FIELD LENGTHS EXCEEDS MAXIMUM.
The sum of the lengths of all fields in a structure exceeds the limit. The default limit is 32,768 bytes. Reduce the number and size of the fields in the file, or eliminate JOINs and cross-references if possible.
This is actually a correction in behavior. The SUM OF ALL FIELDS includes all of the USAGEs described in the MFD as well as any associated DEFINEs. They must be able to fit within LINREC/DATREC. Default size for LINREC/DATREC was 16 kilobytes but in FOCUS 7.2, it has been increased to the maximum of 32 kilobytes.
TABLEing or issuing a CHECK FILE against a MASTER that contains an invalid FIELDNAME, such as a FIELDNAME with special characters like "(", may result in a U591 ABEND RC=00000001 in module FXCMEM. For example:
In the core FOCUS and interface manuals, we say, " FIELDNAME is a name that can consist of letters, digits, and underscore characters. Special characters and embedded blanks are not advised." In our example the "(" are special characters.
If the FIELDNAME is changed from "(" to "T", CHECK FILE... will work. Using the above example, the changed FIELD declaration would look like the following:
JOINing a FIX file to a VSAM file using RECTYPE in the VSAM file results in BLANKs and 0s for any of the VSAM file (XREF) FIELDs.
In the VSAM MFD, the RECTYPE field is described as follows:
In the past, FOCUS would assume that the RECTYPE value is blank. (No value supplied in the ALIAS value is directly after the FIELD keyword.)
However, the NEW MASTER parser is not making this assumption and thus the RECTYPE value is not found in the data file and results in BLANKs /0s displayed for FIELDs from this file due to the JOIN ... TO syntax. (Parent with unique child is the data displayed ( BLANKs or 0s) even if the XREF file instance does not exist.)
Adjusting the RECTYPE FIELD declaration to the following corrected this problem and allowed it to execute properly with SET MASTER=NEW:
The new MASTER parser will not read hexadecimal internal values for RECTYPE within a MFD. The MFD must be strictly character-based. To clarify:
A file consists of multiple records, all but one of which have alphanumeric one-character Record Types in byte 1 of the record. The remaining record type has a packed field beginning in the first byte of the record.
Describing the field as A1 and using ACCEPT = A, ACCEPT = B, and then ACCEPT = 'bin1' TO 'bin2' WHERE bin1 is hex(00), and bin2 is hex(99) causes problems with TED, which cannot read unprintable characters, (which has always been the case) and the new MASTER parser.
Describe the RECTYPE with a USAGE and ACTUAL of I1 (rather than A1). Then the ACCEPT clause specifies the DECIMAL value of the possible RECTYPE. So, assuming RECTYPEs of A, B, S and again hex(00) through hex(99):
These hex values are EBCDIC and can be retrieved from the character chart in the FOCUS for S/390 manual.
|
