File-system summary

The following table shows which types of files can be processed by which types of COBOL programs. An X indicates that a file can be processed by the type of program that is shown at the top of the column.

The table uses these terms:

Small-format
For STL and SdU files, indicates that they are limited to a maximum size of 2 GB. (STL and SdU files created by COBOL for AIX programs before Version 3 had small format.)

For DB2 sequential and relative files, indicates that the maximum number of records is 2 ** 32. DB2 indexed files have no COBOL limit.

To indicate that a COBOL for AIX program should create small-format files, specify runtime option FILEMODE(SMALL).

Large-format
For STL and SdU files, indicates that they can exceed a size of 2 GB; file size is limited to the maximum record size times the maximum number of records.

For DB2 sequential and relative files, indicates that the maximum number of records is 2 ** 64. DB2 indexed files have no COBOL limit.

To indicate that a COBOL for AIX program should create large-format files, specify (or default to) FILEMODE(LARGE).

Table 1. File-system summary
File system and format Is size > 2 GB supported? 32-bit COBOL for AIX Version 3 or later program with current runtime library 64-bit COBOL for AIX Version 3 or later program with current runtime library COBOL for AIX Version 2 program with current runtime library
DB2 small-format See comments that precede table. X X X
DB2 large-format See comments that precede table. X X X1
SdU small-format No X X X
SdU large-format Yes X X X1
STL small-format No X X X
STL large-format Yes X X X1
Line-sequential Yes X X X
RSD Yes X X X
SFS No COBOL limit2 X   X
  1. These programs can open existing large-format files using OPEN INPUT, OPEN I-O, or OPEN EXTEND, and can process those files. However, if these programs create any files using OPEN OUTPUT, those files will have small format.
  2. See Encina publications for detailed limits and requirements.

For further details about DB2 files, see the DB2 publications. For further details about file limits, see the related reference about compiler limits.

related concepts  
File systems