Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
3-167
CREATE Procedure
(Superseded by FILE_CREATELIST_ Procedure )
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Insertion-ordered alternate keys
All of the non-unique alternate keys of a file must have the same duplicate key
ordering attribute. That is, a file may not have both insertion-ordered alternate keys
and standard (duplicate ordering by primary key) non-unique alternate keys. An
insertion-ordered alternate key cannot share an alternate key file with other keys of
different lengths, or with other keys which are not insertion-ordered.
The CREATE procedure returns file 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 may
change if a nonrecoverable 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
altkeyvalue until a match is found on the primarykey-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
altkeytaglen and altkeylen. If the
length of any partition key is greater than this sum, then the file system may fail to
advise the user of the duplicate key condition (indicated by the warning error code
551).
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Queue files
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Queue files are created by specifying file-type .<9> =1 and file-type
.<13:15> =3.
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The key-sequenced-params array must be specified. The minimum key-
len must be 8 bytes, and the key-offset must be 0.
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No alternate-key-params can be specified.
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No partition-key-params array can be specified.
Safeguard Considerations
For information on files protected by Safeguard, refer to the Safeguard Reference
Manual.