LOCK

Control record locking

WTSupported in traditional Synergy on Windows
WNSupported in Synergy .NET on Windows
USupported on UNIX
VSupported on OpenVMS
LOCK:lock_spec

Arguments

lock_spec

One of the following identifiers or corresponding ­values: (n)

Q_NO_LOCK or 0

Do not lock the record.

Q_AUTO_LOCK or 1

Perform automatic locking on the record. (default)

Q_MANUAL_LOCK or 2

Perform manual locking on the record.

Q_NO_TLOCK or 3

Do not lock the record or probe the index tree.

Discussion

The LOCK qualifier specifies whether the operation requires a record lock.

Manual locking is similar to automatic locking, except that manual locking blocks all update reads until either the channel is closed, an explicit ­UNLOCK with the RFA qualifier specified is performed, or the FREE subroutine is called.

Q_NO_LOCK allows you to READ a locked record when it’s opened in update mode. The read record is not locked.

On Windows and UNIX,

Q_NO_TLOCK and Q_NO_LOCK are synonymous on OpenVMS systems.

On the OPEN statement for both non‑ISAM and ISAM files, the Q_NO_LOCK and Q_AUTO_LOCK are the only valid options for the LOCK qualifier.

On the STORE statement, Q_NO_LOCK and Q_MANUAL_LOCK are the only valid options for the LOCK qualifier.

See also