Subfile, AS/400 and expanding subfile

370 pts.
Tags:
AS/400
AS/400 Subfiles
Why is SFLSIZ always 1 greater than SFLPAG in expanding subfile load method?

Software/Hardware used:
as400

Answer Wiki

Thanks. We'll let you know when a new response is added.
Send me notifications when members answer or reply to this question.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Discuss This Question: 8  Replies

 
There was an error processing your information. Please try again later.
Thanks. We'll let you know when a new response is added.
Send me notifications when members answer or reply to this question.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
  • CharlieBrowne
    This seems like a curiosity question not a business problem. To help you go further in like, I suggest you learn to do a little research when you have questions like this. Bring up the IBM DDS manual an read what it has to say.
    41,380 pointsBadges:
    report
  • ToddN2000
    Not knowing what OS version you are using try looking for your ref manual here. http://www.ibm.com/Search/?q=dds+reference+manual&v=17&en=utf&lang=en&cc=us
    12,560 pointsBadges:
    report
  • TomLiotta
    why SUBSIZ is always 1 greater than SUBPAG...
    .
    It isn't. Sometimes SFLSIZ is twice as much as SFLPAG, sometimes it's ten times as big. It can be whatever value that you choose.
    .
    It's possible that you have only seen subfiles that are defined with SFLSIZ being 1 greater than SFLPAG. It's a very common setting.
    .
    Tom
    125,585 pointsBadges:
    report
  • Durgesh813
    probably what you people are saying is right but this question was put to me in an interview, and i googled it also and found the specific question at many times but couldn't find the satisfying answer to it. thanks for your replies by the way. i will try and search more into it.
    370 pointsBadges:
    report
  • TomLiotta
    The problem is that the question is incorrect. . SFLSIZ is not always 1 greater than SFLPAG for expanding subfiles. It is extremely often that it is 1 greater; but that's because it's how most developers learned to do it, it's a value that works reasonably well and few developers ever learn why values other than 1 can sometimes be better. . Any value greater than 1 would also work (as long as it didn't exceed 9999.) And for many subfiles, other values would actually be better. . For actual best performance across the system, the SFLSIZ should represent the number of records that you reasonably expect to be put into the subfile. If your subfile has 15 records per page, and you expect that most users will page down three to five times on average, then you should set SFLSIZ to be something like 75 (which would be 60 greater than SFLPAG, i.e., 4*15 greater in order to expect three to five pages added). . But almost no one cares about whether the size estimates make any difference, so almost everyone simply uses "1 greater than SFLPAG". The subfile still can be expanded. It just has to make more memory allocations while it runs. After RISC systems came around, system performance issues like that one were less important. . For that interview question, the answer might simply be "Because it works. Why use any other value when the benefit is so small? Besides, almost everyone recognizes what the value means. The use of other values is mostly irrelevant in current applications; and if it's relevant in this job, I'll need a significantly higher salary than I'd normally expect." . Tom
    125,585 pointsBadges:
    report
  • Sofarsogood
    Lol! Tom, I like your answer!
    60 pointsBadges:
    report
  • TomLiotta
    Note that it wasn't totally a humorous answer. And it also assumes that the question indeed asked "always" 1 greater. Such interview questions can indicate a troublesome place to work. . Old technology, old ways of doing things, not allowed to use modern techniques. Career advancement is difficult, as is getting any practical experience with anything that would be useful in a really good job. A higher rate of pay is called for. . But the assumption about the question would need to be made based on all other questions. Such a question might be crafted to see if an actual good answer is offered. Of course, that would also be a reason to think of higher pay. . Tom
    125,585 pointsBadges:
    report
  • Durgesh813
    LOL tom thanks.
    370 pointsBadges:
    report

Forgot Password

No problem! Submit your e-mail address below. We'll send you an e-mail containing your password.

Your password has been sent to:

To follow this tag...

There was an error processing your information. Please try again later.

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Thanks! We'll email you when relevant content is added and updated.

Following