Communicator e3000 MPE/iX Release 6.5 (Non-Platform Software Release C.65.00 (30216-90291)

42 Chapter3
Growth Solution
MPE/iX Large Files Overview
BUILD Command Changes
With the first release of Large File support, only two file types are being supported for
Large File sizes; ordinary, fixed length record files, and KSAM files. Because of inherent
limitations in the internal format of KSAMXL and CM KSAM files, it is necessary to
introduce a new type of KSAM file, KSAM64 files, in order to go beyond a 4GB sized KSAM
file. The internal format of the KSAM64 index area is structured so that file sizes from 1
record all the way to 1TB can be easily supported.
While unfortunately, this means that MPE/iX supports three different varieties of KSAM
files (CM KSAM, KSAMXL and KSAM64), the good news is that all three of these file types
are functionally equivalent and can be used interchangeably by programs. The only
external difference between KSAMXL and KSAM64 files is that a different file type must
be used to create them. Other than this, all other KSAM options are specified identically.
The only change to the BUILD command is the addition of the KSAM64 file type keyword.
This keyword can be included in the BUILD command as a replacement for the KSAMXL
keyword. KSAM64 files may be of any file size, but are the only KSAM file type that can be
larger than 4GB. The new syntax for the BUILD command is:
BUILD filereference
[F]
[;REC=[[recsize][,[blockfactor][,[U][,BINARY]]]]]
[V][,ASCII ]
[B]
[{;CCTL }]
{;NOCCTL}
[;TEMP]
[;DEV=[[dsdevice]#][device]]
[;CODE=filecode]
[;DISC=[numrec][,[numextents][,[initialloc]]]]
[{;RIO }]
{;NORIO}
{;STD }
{;MSG }
[{;CIR }]
{;KSAMXL}
{;SPOOL }
{;KSAM64}
[;ULABEL=numlabels]
[;KEY={^filereference2}]
{keyinfo }
[;FIRSTREC=recnum]
[{;REUSE }]
{;NOREUSE}
[;LANG={langid }]
{langname}
[{;DEFBLK}]
{;OPTMBLK}
In order to create a Large File, all that is required is to specify a file limit of a sufficiently
large number. For example, to create a ordinary, fixed length record file with 80 byte