Re: reorg HUGE file

[D.BALE@xxxxxxxxxxxxx]

Stupid answer: because it's legacy city, baby!  Thinking out loud here: What
if an application implicitly relied on FIFO for duplicate keys on the logicals
whose AP might be one used from another LF?  I guess it reinforces the
importance of knowing:  Does the system default to FIFO for duplicate keys?  I
decided to RTFM and the answer appears to be, "unpredictable".  In fact, I was
a little confused by what I found in the DDS reference under the FIFO keyword:

  If you do not specify FCFO, LIFO, FIFO, or UNIQUE, records with
  duplicate key values are retrieved in first-in first-out (FIFO),
  last-in first-out (LIFO), or first-changed first-out (FCFO)
  order, but the order in which they are retrieved is not guaranteed.

Sounds as clear as mud to me.  But it would seem to indicate that if we
haven't had any problems so far in all the years we've used these logicals
with duplicate keys that are "unpredictably" retrieved, perhaps it would make
sense to look at those logicals again.

In the short term, though, does it make sense to recreate the logicals in this
sequence?: L3, L8, L6, L2.  Would not L8, L6, & L2 all use L3's access path?
I just checked one of our branch boxes, and only L2 implicitly shares an
access path.  If I could get all four to share one access path, I could
recover another 3 GB of DASD.  (Every little bit helps, eh?)

And who knows, there might be a bunch more scenarios like this.  Does anyone
have a tool that identifies logicals whose access paths are eligible to be
shared and list the disk space savings for doing so?  Sounds like a
program-of-the-month thingy to me.

Dan Bale
IT - AS/400
Handleman Company
248-362-4400  Ext. 4952

-------------------------- Original Message --------------------------
Stupid question, I know, but why have L6, L8 or L2 at all?

---------
Noticing that L6 could use the access path of L8, and L8 could use the access
path of L3, and L2 could use the access path of any of the other listed
logicals, does the system recognize this and build L3 before L8, L8 before L6,
and build L2 last?  (What's the term that describes a logical file using the
access path of another?)  Or do key duplicates follow FIFO by default?  How do
I tell?
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