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X Table 10. Statements Affecting Record Locking |
X Statement |
X Comments |
X CLOSE
X
X |
X After you successfully CLOSE a file, any record and file
X locks held by the file connector on the closed file are
X released. |
X DELETE
X |
X You cannot DELETE a record that any other file connector has
X LOCKed. |
X OPEN
X
X |
X If you attempt to OPEN a file that another file connector
X has LOCKed, the OPEN fails and you receive a 'file locked'
X file status (98). |
X READ
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X |
X For files opened for INPUT, READ statements will not acquire
X a record lock.
X If you attempt to READ a record that another file connector
X has LOCKed, the READ fails and you receive a 'record locked'
X file status (FS 99). For a sequential READ, the setting of
X the file position indicator is unaffected. For a random
X READ, the setting of the file position indicator is
X unspecified.
X When you specify the READ statement at the end of the file
X (when no more records exist), the AT END condition is
X returned regardless of any sharing of the file. This
X situation can occur if the file is opened in EXTEND mode by
X another file connector.
X If you OPEN the file for I-O and specify the LOCK MODE IS
X AUTOMATIC clause, each record is locked as it is read and
X released by the next I-O statement accessing the file
X connector. |
X REWRITE
X
X
X
X |
X You cannot specify the REWRITE statement for a record that
X another file connector has LOCKed (the file is exclusive).
X If LOCK MODE IS AUTOMATIC is specified (the file is
X shareable), you can use the REWRITE statement to release a
X record that is LOCKed. |
X START
X
X
X |
X You cannot use the START statement to LOCK a record or to
X detect if a record is LOCKed. However, the START statement
X will release an existing LOCKed record if you have specified
X the LOCK MODE IS AUTOMATIC clause. |
X WRITE
X
X
X
X
X
X
X
X
X
X |
X If two or more file connectors add records to a file by
X sharing the file after opening it in EXTEND mode, the
X following occurs:
X � Sequential files: the records are in an unspecified
X order.
X � Relative files: the relative key values returned are
X ascending but not necessarily consecutive.
X � Indexed files: the order of the alternate keys allowing
X for duplicates is unspecified.
X When you specify LOCK MODE IS AUTOMATIC, a successful WRITE
X statement releases a LOCKed record. |