To use dynamic locking,
SPD Server tables must be part of a named SPD Server domain. When
dynamic locking is enabled for a domain, all of the SPD Server users
that access tables in that domain automatically use dynamic locking.
The SPD Server clients do not need to set any additional parameters
to take advantage of the benefits of dynamic locking.
When SPD Server proxy
processes receive concurrent update, append, insert, and delete commands,
the commands are sequentially queued and then executed in order of
arrival. Only one Update operation is performed on a table at any
one time. Read requests can be executed at any point during an Update
operation. Read requests get the most recent information that is available
in the table, based on the last physical update to disk.
Dynamic locking is not
a replacement for using record-level locking when the user requires
SAS record-level integrity across multiple clients. Reading a record
using dynamic locking does not guarantee that the record will not
change before a subsequent read or update is executed. If a client
needs a true record-level lock, then the record-level locking protocol
should be used.
Note: A domain that has dynamic
locking enabled cannot also use record-level locking.