Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (F)
Guardian Procedure Calls Reference Manual—522629-013
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FILE_CREATELIST_ Procedure
extent sizes (items 50, 51, and 91 in item-list) and maximum extents (item 52)
yield a file size greater than (2**32) - 4096 bytes (approximately four gigabytes) or
a partition size greater than 2**31 bytes (two gigabytes).
•
Insertion-ordered alternate keys
All the nonunique alternate keys of a file must have the same duplicate-key-
ordering attribute. That is, a file cannot have both insertion-ordered alternate keys
and standard (duplicate ordering by primary key) nonunique alternate keys. An
insertion-ordered alternate key cannot share an alternate key file with other keys of
different lengths or with other keys that are not insertion-ordered.
The FILE_CREATELIST_ procedure returns error 46 if the rules of usage for
insertion-ordered alternate keys are violated.
When an alternate-key record is updated, the timestamp portion of the key is also
updated. Alternate-key records are updated only when the corresponding
alternate-key field of the primary record is changed.
The relative position of an alternate-key record within a set of duplicates might
change if an unrecoverable error occurs during a writeupdate of the primary
record.
There is a performance penalty for using insertion-ordered duplicate alternate
keys. Updates and deletes of alternate-key fields force the disk process to
sequentially search the set of alternate-key records having the same alternate key
value until a match is found on the primary-key-value portion of the key. (The
value of the timestamp field in an alternate key 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).
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Queue files
To create a queue file, specify item 71 as described under the “FILE_CREATE_
Procedure.” For more information, refer to the FILE_CREATE_ procedure. Some
item codes are incompatible with queue files; no partitions or alternate keys can be
defined for queue files.
OSS Considerations
This procedure operates only on Guardian objects. If an OSS file is specified, error
1163 is returned.