ALLBASE/SQL Reference Manual (36216-90216)

Chapter 5 173
Concurrency Control through Locks and Isolation Levels
Use of Locking by Transactions
reduction of throughput that it is obviously not desirable in most situations.
Another cost of locking is the use of shared memory resources. Each lock requires the use
of some runtime control block space. The more locks used by a transaction, the more
memory required for control blocks. This is especially important for PUBLICROW tables,
which usually require more locks than PUBLIC tables.
To minimize the costs of locking on PUBLIC and PUBLICROW tables, you should design each
transaction in such a way as to lock only as much data as necessary to keep out other
transactions that might conflict with your transaction's work. The following sections
explain the features of ALLBASE/SQL that you can use to accomplish this.