maximum records calculation

Deepa.m · New User Joined: 28 Apr 2005 Posts: 99

How to calculate the maximum records the PS can store using the space parameter.
ex: SPACE(150,(100,30))

what will be the maximum records that it can hold. what is default for AVGREC.is it units or kilobytes?

MGIndaco · Posted: Thu May 19, 2005 7:07 pm

Try to see this topic:
http://ibmmainframes.com/viewtopic.php?t=1683&highlight=average

Or access to IBM manual and see example 6:
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/iea2b650/12.55.6?SHELF=&DT=20040712170508&CASE=

Deepa.m · New User Joined: 28 Apr 2005 Posts: 99

I want to know the formula to calculate the maximum records for the given example
SPACE(150,(100,30))

Can anyon e provide the same.

Deepa.m · New User Joined: 28 Apr 2005 Posts: 99

any updates?

Deepa.m · New User Joined: 28 Apr 2005 Posts: 99

I was not able to browse the link you provided..Just had a look at example 6.
This is what i want to know..Thanks MGIndaco

vidyasaraswathi · New User Joined: 10 May 2005 Posts: 72

Here is some information:
-------------------------------------------
SPACE(trk,(100,30)) :
This results in a primary allocation of 100 tracks and up to 15 extents of 30 tracks maximum each.
The maximum space that could be allocated is:100 + (30 * 15) = 550 tracks.

TRK - specifies that space is to be allocated by tracks. 1 track on 3390 disk storage equals 56,664 bytes.

Based on this, you can calculate the max no of bytes = 56,664 * 550

Also consider the following example:
// DCB=(LRECL=80,BLKSIZE=9040,RECFM=FB)

Here No of Records= 9040/80 = 113

LRECL=x - specifies the record length of the stored data in bytes. LRECL=80 indicates a logical record length of 80 bytes. For variable-length records, LRECL indicates a maximum record length.
BLKSIZE=y - specifies the physical block length of the data in bytes. For fixed-record length records, 'y' must be a multiple of the LRECL value 'x'. The maximum blocksize allowed on 3390 disk storage is 28,332 (1/2 track) but a maximum of 28,000 is recommended.

Thanks and Regard,
Vidya Bhat