Guardian Procedure Calls Reference Manual

record is not stored in the primary record.) The performance cost rises as the number of records
having duplicate alternate-key values increases.
If an insertion ordered alternate-key file is partitioned, the length of each partition key should
be no greater than the total of the alternate-key tag length and the alternate-key length. If the
length of any partition key is greater than this sum, then the file system might fail to advise the
user of the duplicate-key condition (indicated by the warning error code 551).
• Queue files
To create a queue file, specify item 71 as described in Table 17. Some item codes are
incompatible with queue files; no partitions or alternate keys can be defined for queue files.
• In the item-list parameter, if item 41 (file type) has a value of 3 (key-sequenced), item 90
(number of partitions) has a value between 16 and 63, and item 195 (format type) specifies
a format 2 file, the target of the creation is an enhanced key-sequenced file.
• Creating key-sequenced files with increased limits
In H06.28/J06.17 RVUs with specific SPRs and later RVUs, format 2 legacy key-sequenced
files and enhanced key-sequenced files can be created with increased file limits. (For a list of
the required H06.28/J06.17 SPRs, see SPR Requirements for Increased Enscribe Limits for
the H06.28/J06.17 Release (page 31).) The creation of a file with increased limits occurs if
item code 41 of the item-list parameter has a value of 3 (key-sequenced), item code 195
(file format) is either not specified or specifies a format 2 file, and at least one of the following
is specified:
◦ Item code 90 (number of partitions) has a value between 64 and 127
◦ Item code 44 or 197 (block length) has a value of 32,768 bytes (or a value greater than
4096 bytes, which is rounded up to 32,768 bytes)
◦ Item code 46 (key length) has a value of 256 to 2048 bytes
Note the following considerations when using these increased limits with the FILE_CREATELIST_
procedure:
◦ The CEXTDECS file uses the unsigned short data type (instead of short) for the
values length parameter.
◦ Item code 43 or 196 (logical record length) may have a value up to 27,648 bytes
(depending on the block length value.)
◦ Item code 101 (alternate-key descriptor) may contain an extended key length.
◦ If item code 104 (alternate file names) is specified, the filenames specified in the values
parameter may specify any key-sequenced file, including those with increased limits.
◦ If the target file uses any increased limits features, its primary partition must be on a system
running an H06.28/J06.17 RVU with specific SPRs or a later RVU. (For a list of the
required H06.28/J06.17 SPRs, see SPR Requirements for Increased Enscribe Limits for
the H06.28/J06.17 Release (page 31).) If the target file uses the increased partitions
limit feature (secondary partition count greater than 63), its primary partition must be
located on the system with the creating application.
◦ If the target file uses only the increased partitions limit feature (secondary partition count
greater than 63), the secondary partitions may be located on earlier RVUs. However, if
the target file uses increased limits features other than the increased partitions limit feature,
the secondary partitions must be located on systems running an H06.28/J06.17 RVU
with specific SPRs or a later RVU.
◦ The key-length of a key-sequenced file is limited to 255 bytes when either the index or
data compression option is specified. If an attempt is made to create a key-sequenced
402 Guardian Procedure Calls (F)