Author: Robert Sample
Subject: Reply to: VSAM File free space
Posted: Wed Apr 04, 2018 9:59 pm (GMT 5.5)
Yes, EXAMINE is looking at every CI so it will be the most accurate accounting of free space. It is not possible to reconcile the LISTCAT output with the EXAMINE output all the time -- this data set shows why. Even though the AVGLRECL and MAXLRECL are 4,000 (implying a fixed record length), when I divide the HI-U-RBA by the 8,472,700 record count the actual average record length is 1,296 (1295.65 rounded up) and EXAMINE states the longest record is 4,003 bytes. Hence some (maybe all) of the 535,992 CI have unused space in them -- EXAMINE will count this as free space even though LISTCAT will not.
_________________
TANSTAAFL
The first rule of code reuse is that the code needs to be worth re-using.
"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." -- Donald Knuth
Subject: Reply to: VSAM File free space
Posted: Wed Apr 04, 2018 9:59 pm (GMT 5.5)
Yes, EXAMINE is looking at every CI so it will be the most accurate accounting of free space. It is not possible to reconcile the LISTCAT output with the EXAMINE output all the time -- this data set shows why. Even though the AVGLRECL and MAXLRECL are 4,000 (implying a fixed record length), when I divide the HI-U-RBA by the 8,472,700 record count the actual average record length is 1,296 (1295.65 rounded up) and EXAMINE states the longest record is 4,003 bytes. Hence some (maybe all) of the 535,992 CI have unused space in them -- EXAMINE will count this as free space even though LISTCAT will not.
_________________
TANSTAAFL
The first rule of code reuse is that the code needs to be worth re-using.
"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." -- Donald Knuth
