Attributes of receive files

This section describes the attributes of new receive files created by openFT (indicated by the entry "N" in the table on the next page).

The attributes described here also apply to receive files with which openFT overwrites existing files (indicated by the entries "O" and "D + N" in the table on the next page).

The following points also apply:

If, during transfer, the receive file is to be retained, i.e. you only want to extend the receive file (entry "E" in the table below), the attributes of the existing file are retained. In this case, transfer only takes place if the format of the new data is compatible with the attributes of the existing file. Otherwise, the transfer request is rejected with an error message or is canceled.

In all cases where a receive file is to be extended, note that the z/OS Data Management System permits a total of only 16 "extents" for PS and PO data sets. In the case of PDSE data sets, up to 123 extents are possible. If this is insufficient for the extension of the receive file, the file transfer is rejected with an error message or is canceled.

The Data Management System also issues an error message.

There are three factors which determine whether openFT creates a new receive file, overwrites an existing file or extends an existing file:

• the value of the WRITE-MODE operand in the NCOPY command,

• the type of the receive file, and

• whether or not a file with the same name already exists.

The following table shows which combinations of these factors cause a new file to be created or an existing file to be overwritten or extended for the purpose of storing the data transferred. The procedure always applies to the entire file (or to the PO/PDSE data set if a PO/PDSE member is being transferred).

Type of receive file	Existing file with the same name	Value of the WRITE-MODE operand
		*NEW	*REPLACE	*EXTEND
PS data set	no	N	N	N
	yes	---	O	E
VSAM file	no	N	N	N
	yes	---	D + N	E
openEdition file	no	N	N	N
	yes	---	D + N	E
Library transfer:
PO or PDSE data set	no	N	N	---
	yes	---	D + N	---
Member transfer:
PO or PDSE data set does not exist		N	N	N
PO or PDSE data set exists, member does not exist		E	E	E
PO or PDSE data set exists, member exists		---	E	E

Explanation:

N	A new receive file is created.
D + N	The file is deleted (thus releasing the disk storage occupied by it) and a new file is created on the same volume.
O	The file is overwritten. In contrast to "D + N", the disk storage previously occupied is not released. It is first overwritten and then extended, if necessary, provided that this is possible. To do this, the existing file must be of the same type as the file to be created, otherwise the same procedure is adopted as for "D + N".
E	The file is extended.
---	No file transfer takes place (the transfer request is rejected).

For a better understanding of the processes involved in member transfer, refer to section“Notes on transferring entire PO or PDSE data sets”.

Some file attributes (e.g. the file name) are derived from specifications in the NCOPY command, from openFT parameters or from local system defaults.

Most of the attributes of a receive file, however, are determined by the corresponding attributes of the send file. The following factors determine the extent to which the file attributes of these two files can be mapped onto one another:

• Which attributes are transferred via the link involved?
  A distinction is made between the following types of link:

  • Homogeneous link: Link between two openFT (z/OS) systems

  • Heterogeneous link: Link between openFT (z/OS) system and another FT system, e.g. openFT (BS2000)

• How well can a receive file attribute be derived from a transferred attribute or a combination of transferred attributes?

  The transferred attributes must be converted into attributes of the generated receive file. The rules governing this procedure are described below in detail.
  The transferred attributes themselves are derived from the attributes of the send file; in many cases, the rules applied are complementary to those described here.

The following send file attributes are transferred via both homogeneous and heterogeneous links:

• file size

• (maximum) record length

• record format (U,V,F)

The following additional attributes can be transferred via a homogeneous link:

• block length

• number of directory blocks

• spanned records attribute

• blocked records attribute

• control character attributes