Multiple users wish to update a table at the same time. In this scenario, the open for write can be performed once by a transaction at the beginning of the day, and postings can be made throughout the day with periodic storing (ST command). The table can be opened either with or without a LOCK-LATCH password that allows multiple users to update the table.
Since the table may be shared among multiple update transactions, to prevent interference there must be application specific enqueues against the table while an update is going on. These must be performed by each user in each user program.
If a table is being updated by more than one user at a time, the IC, RC, and DC commands should not be used. These commands rely on a previously determined position (usually set by a Fetch by Key request) that may be changed by another user inserting or deleting a row in the same table.