I just tried a browse on a sequential file with 6,355,209 records, using 6,621
cylinders, finding a 31-byte key at the beginning of the record, where the key
is found at record number 6,355,208.
I normally have 256 MB of region, but for this test I changed it to 48000K.
Before Browse:
Limit In-use Avail
Below 16M: 9060K 400K 8660K
Above 16M: 49024K 5240K 43784K
After entering Browse of data set:
Limit In-use Avail
Below 16M: 9060K 468K 8592K
Above 16M: 49024K 5280K 43744K
After f 1 'I000065800232001005001GIORFIORC' command completed (in about 44
seconds):
Limit In-use Avail
Below 16M: 9060K 468K 8592K
Above 16M: 49024K 6876K 42148K
After exiting Browse:
Limit In-use Avail
Below 16M: 9060K 440K 8620K
Above 16M: 49024K 5240K 43784K
This is on z/OS 2.4 on a z14.
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Farley, Peter
Sent: Tuesday, May 23, 2023 4:19 PM
To: [email protected]
Subject: Re: Why does ISPF BROWSE abend with S878 searching a large sequential
file?
Possibly. But if so we are in a lot more trouble than annoying abends out of
TSO, as this is customer data with legal archiving requirements. If it is
somehow corrupted by compression (not sure at this point if that file is using
IBM software compression or zEDC hardware compression) we have MUCH larger
issues.
IMHO it is probably just BAD (broken as designed) BROWSE code, but with OCO
there is no way for an ordinary customer to know.
Peter
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Schmitt, Michael
Sent: Tuesday, May 23, 2023 4:56 PM
To: [email protected]
Subject: Re: Why does ISPF BROWSE abend with S878 searching a large sequential
file?
EXTERNAL EMAIL
I agree that Browse isn't supposed to require enough memory to hold the file,
so it should work.
But.
Is "compressed data" the key? How is it compressed? Does the fact that it is
compressed mean that more data has to be in memory? Or is it going wild on
decompression, such as if the data is corrupted so the length is wrong? (Like
how it is possible to create a tiny .ZIP file that decompresses to terabytes.)
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Farley, Peter
Sent: Tuesday, May 23, 2023 3:13 PM
To: [email protected]
Subject: Why does ISPF BROWSE abend with S878 searching a large sequential file?
This has happened to me twice this afternoon, and several other times in the
last few months - I am trying to browse (from ISPF 3.4) a quite large
sequential file (> 14500 cylinders of compressed data) for a record with a
specific 31-byte key at the beginning of the record, and browse abends with
S878 and throws me off TSO entirely, requiring me to login again each time.
My TSO logon region size is set to 48000, so what in the world is making browse
consume so much memory that it runs out and crashes my TSO session entirely?
I know, OCO prevents anyone knowing for sure, but if you have any clue I'd
appreciate knowing the answer.
I've been forced to search that file using SORT in a batch job to keep the
frustration level lower.
Peter
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