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EXCLUSIVE.USE (EXU)
EXCLUSIVE.USE (EXU)
Syntax
Reference
The EXCLUSIVE.USE; command is a means of restricting access to the database records
of an Ispec. The Ispec must be read in the logic in which the lock is applied. The command
locks all of the records of a Component, or all records of all Events.
This command is ignored in LDA Run Time.
Restrictions on record access are:
$ For UNIX and MCP based LINC Systems, records may be read by other users, but
cannot be updated until either the end of the current transaction, or an END.USE;
command (in a Report).
$ For OS 2200 based LINC Systems, records remain inaccessible to other users until
either the end of the current transaction, or an END.USE; command (in a Report).
The EXCLUSIVE.USE; command is ignored if a SECURE; command option has been
applied to the same Ispec in the same logic. (The effect of the EXCLUSIVE.USE; command
can also be achieved by locking a control-type record.)
EXCLUSIVE.USE; enables faster access at execution time, as no locks have to be applied,
but has the potential disadvantage of locking out all other users of the Ispec until the lock
is released.
Caution
Excessive use of the EXCLUSIVE.USE command may result in:
$ Long waits for other users
$ Deadlocks
$ An abort at runtime
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"Integrity" in your LINC Generate Operations Guide.
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