Last time I looked, AIX with upgrade (required for the OP's described
conditions) was a *VERY POOR* performer.
However, with the small proportion of updates later described, this does
not seem like it would have a disproportionate impact.
Create an AIX pointing at the file with the AIX key being
e the DEFERW in Ron's example.
>
> HTH
>
> Peter
>
> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On
> Behalf Of Ron Hawkins
> Sent: Wednesday, April 04, 2012 12:35 AM
> To: IBM-MAIN@bama.ua.edu
> Subject: Re:
[mailto:IBM-MAIN@bama.ua.edu] On Behalf
Of Joel C. Ewing
Sent: Wednesday, April 04, 2012 9:13 PM
To: IBM-MAIN@bama.ua.edu
Subject: Re: VSAM help wanted for random reads
On 04/04/2012 10:37 AM, Chip Grantham wrote:
> We have an application like this, that is multiple record types in the
> same KSD
At 16:33 -0700 on 04/03/2012, Frank Swarbrick wrote about Re: VSAM
help wanted for random reads:
The idea of putting the record type at the end rather than the
beginning is an interesting idea.Ý Unless there's some way of doing
that without having to change any programs I don't
VSAM keeps up with this stuff too. Wouldn't hurt to do a reorg every once
in blue moon too!
In a message dated 4/4/2012 6:12:16 P.M. Central Daylight Time,
martin_pac...@uk.ibm.com writes:
out of SMF 62 and 64 that would've told you how much "write" activity you
had - and a lot else bes
April 4, 2012 1:34 PM
> Subject: Re: VSAM help wanted for random reads
>
> Not to suggest YOU should've done this but you can get useful statistics
> out of SMF 62 and 64 that would've told you how much "write"
> activity you
> had - and a lot else besides.
>
r of Excellence, IBM
+44-7802-245-584
email: martin_pac...@uk.ibm.com
Twitter / Facebook IDs: MartinPacker
Blog:
https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker
From:
Frank Swarbrick
To:
IBM-MAIN@bama.ua.edu,
Date:
04/04/2012 16:59
Subject:
Re: VSAM help wanted for
On 04/04/2012 10:37 AM, Chip Grantham wrote:
We have an application like this, that is multiple record types in the
same KSDS. We found that if we had a FD for the type '4' records and a FD
for the type '5' records (that is two DDs pointing to the same file), that
each kept a separate sequence s
essage -
> From: "Farley, Peter x23353"
> To: IBM-MAIN@bama.ua.edu
> Cc:
> Sent: Wednesday, April 4, 2012 7:00 AM
> Subject: Re: VSAM help wanted for random reads
>
> Be very cautious using DEFERW with BLSR unless you already have a good backup
> of
>
bject: Re: VSAM help wanted for random reads
>
> We have an application like this, that is multiple record types in the
> same KSDS. We found that if we had a FD for the type '4' records and a
> FD
> for the type '5' records (that is two DDs pointing to the same
We have an application like this, that is multiple record types in the
same KSDS. We found that if we had a FD for the type '4' records and a FD
for the type '5' records (that is two DDs pointing to the same file), that
each kept a separate sequence set in storage and it ran faster. You might
t; From: Ed Gould
>To: IBM-MAIN@bama.ua.edu
>Sent: Tuesday, April 3, 2012 6:24 PM
>Subject: Re: VSAM help wanted for random reads
>
>Frank,
>
>Thanks for reporting back.
>One request is there somehow to paste the results so they match up with the
>headers ?
>
ssage-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of
Ron Hawkins
Sent: Wednesday, April 04, 2012 12:35 AM
To: IBM-MAIN@bama.ua.edu
Subject: Re: VSAM help wanted for random reads
Frank,
It is terrific that you are getting an improvement with BLSR.
I suspect
: VSAM help wanted for random reads
Sent by:
IBM Mainframe Discussion List
Frank,
It is terrific that you are getting an improvement with BLSR.
I suspect you are using a vanilla copy of an example in the BLSR manual
similar to Peter Farley's example in his post. The problem is these
Frank,
It is terrific that you are getting an improvement with BLSR.
I suspect you are using a vanilla copy of an example in the BLSR manual
similar to Peter Farley's example in his post. The problem is these parms do
not get the best performance from BLSR.
The missing value is DEFERW.
Frank,
Thanks for reporting back.
One request is there somehow to paste the results so they match up
with the headers ?
Ed
On Apr 3, 2012, at 6:33 PM, Frank Swarbrick wrote:
Several good ideas given.
My sysprog installed BLSR and I got very good results:
Without BLSR:
-
Several good ideas given.
My sysprog installed BLSR and I got very good results:
Without BLSR:
-
-TIMINGS
(MINS.)--
-PAGING COUNTS
-STEPNAME
PROCSTEP RC EXCP
CONN
TCB SRB
CLOCK SERV
WORKLOA
For right now, apply to '4' accounts, save misses to a file, then
close and open for input and process the '5' account and report the
misses.
I assume the input is sorted into ascending order for the fast
results. How about changing the key definition so the account number
is in front and the acc
Have you looked at adding BUFNI
and/or BUFND to the JCL DD ?
Do you have any vendor products doing VSAM tuning ? possibly doing buffer
tuning..
Regards,
Doug
Sent from my iPhone
On Apr 3, 2012, at 17:55, Steve Comstock wrote:
> On 4/3/2012 3:23 PM, Frank Swarbrick wrote:
>> Current program
On 4/3/2012 3:23 PM, Frank Swarbrick wrote:
Current program does the following (in COBOL!).
- Opens KSDS for I-O
- Sequentially processes another file (non-VSAM).
- For each record in the non-VSAM file it attempts a random (keyed) read of
arecord on the KSDS file. The key is, essentially, a conc
Should have mentioned, that is a thought we've considered. And we may end up
doing. Just wanted a better way, if there is one.
Frank
>
> From: Fred Hoffman
>To: IBM-MAIN@bama.ua.edu
>Sent: Tuesday, April 3, 2012 3:34 PM
>Subject: Re:
: IBM-MAIN@bama.ua.edu
>Sent: Tuesday, April 3, 2012 3:33 PM
>Subject: Re: VSAM help wanted for random reads
>
>Frank,
>
>Try using batch local shared resources (SUBSYS=BLSR) for the file, and specify
>at least twice as many index buffers for it as you have levels in the KS
One (of many) possible explanations is that there are more hits on the type 5
and more rewrites. Depending on your VSAM options, a rewrite can be -very-
expensive.
Try a comparison run without the type 4 logic.
Also try BLSR and DISP=OLD. That makes the best use of VSAM buffering.
Run the 4's then run the 5's. It can't be that simple.
-Original Message-
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of
Frank Swarbrick
Sent: Tuesday, April 03, 2012 4:24 PM
To: IBM-MAIN@bama.ua.edu
Subject: VSAM help wanted for random reads
Current prog
Frank,
Try using batch local shared resources (SUBSYS=BLSR) for the file, and specify
at least twice as many index buffers for it as you have levels in the KSDS.
For example:
//MYKSDS DD SUBSYS=(BLSR,'DDNAME=MYKSDS#','RMODE31=ALL',
// 'MSG=I','BUFND=256','BUFNI=10')
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