Cost-Based Optimization of Integration Flows - Datenbanken ...

5 Multi-Flow Optimization
the query of o 3 (Invoke) such that additional information for all messages of the batch is
loaded from the external system, which led to an improvement due to fewer plan instances.
The naïve (time-based) approach mainly depends on the waiting time. An increasing
waiting time causes a larger number of messages in every batch and therefore it causes a
decreasing number of batch plan instances. As a result, the relative execution time per
message might decrease and message throughput increases. However, the naïve approach
has the following major drawback:
Problem 5.4 (Distinct Messages in the Batch). Due to the simple (time-based) model
of collecting messages, there might be multiple distinct messages in the batch according to
the attributes used by the operators of P ′ . It follows that we need to rewrite the queries to
external systems. Figure 5.3 illustrates common cases of those queries.
Q:
Q’:
Q’:
service interface
get( x )
Q:
σ A=100
S
σ A=100 ᴠ A=200
S
σ A