Enscribe Programmer's Guide

Table 7 Comparison of Format 1 Versus Format 2 Files (continued)

Format 2 FilesFormat 1 FilesFile Attribute or Procedure Call

AllAllFile Types

8-byte (64-bit) primary-key value4-byte (32-bit) primary-key valueNon-Key-Sequenced Primary Key Value

in Alternate Key Records

For unstructured format 1 files in 512 byte disks such as ESS/JBOD, the pri-extent-size and sec-extent-size must both be

divisible by 14. If the file is unpartitioned, DP2 automatically rounds up the size. The maximum page size that is divisible

by 14 is 65492, therefore the EOF (16 extents of 65492 pages) is 2,146,041,856 bytes.

Partition and File Format Compatibility

All partitions of a file are created with the same file format version (format 1 or 2).

For non-key-sequenced files, a partition that is created independently must have the same format

as all the other partitions of the file. If that partition does not have the same format, it cannot be

opened and a warning message of FEPARTFAIL is displayed.

Key-sequenced files with a mixture of partition formats, providing they meet all other compatibility

requirements, are accessible and can be opened. This should assist in the process of converting

large partitioned key-sequenced format 1 files to large partitioned key-sequenced format 2 files.

NOTE: Partition compatibility requires the same record and block sizes in all partitions. This has

consequences for some file types. In particular, for key-sequenced files with some record/block

size combinations, it may not be possible to have a mixture of formats among the partitions.

File Size Limits

Applications can encounter problems if the files it uses are too large. The following paragraphs

discuss limits and considerations for the different Enscribe file types.

Files Secured With Enhanced File Privileges

When format 1 Enscribe files are secured using the new OSS file privilege attributes, those files

are limited to approximately 953 secondary partitions (file label size of 3960 bytes). These new

file privilege attributes cannot be set on format 1 Enscribe files that have approximately 945

partitions (a file label size of 3926 bytes or greater).

These restrictions also apply to format 1 partitioned files. Format 2 Enscribe files are not affected.

Users with files affected by this limitation may reorganize the files to create larger primary and

secondary extents. Larger primary and secondary extents result in a lesser number of extents for

the same file. The following command lists the attributes of a file including the “File Label” size:

fup info <filename>, detail

Use the following commands to create a new file with larger primary and secondary extent sizes:

fup dup <filename>, <new-filename>, ext (pri-ext-size), sec-ext-size)

Partition Limit

A single format 1 partition (or an unpartitioned format 1 file) is limited to a maximum of 2 GB

minus 1 MB. If you try to create a file or partition with extent sizes and maxextents that specify a

potential greater than this amount, then a format 2 file will be created (if the default system format

selection is in effect). If 2 GB minus 1 MB is exceeded when format 1 is explicitly specified, or if

the size exceeds 1 terabyte, then error 583 or 21 is returned.

Key-Sequenced and Queue Files

Legacy key-sequenced files can have up to 16 partitions and the maximum possible size is ~16

TB. EKS key-sequenced files without increased limits can have up to 64 partitions and the maximum

possible size is ~63 TB. However, key-sequenced files greater than 2 GB may encounter problems

48 General File Creation and Access Information