Apama 10.15.0 | Developing Apama Applications | Developing Apama Applications in EPL | Working with Streams and Stream Queries | Using dynamic expressions in stream queries | Understanding when the correlator evaluates particular expressions | Using dynamic expressions in equi-joins
 
Using dynamic expressions in equi-joins
The format of a query that contains an equi-join is as follows:
from x in s1 join y in s2 on j1 equals j2 ...
Suppose that j1 and j2 are dynamic expressions that return the left and right join keys for each input item. The correlator evaluates these expressions once for each input item when it enters the window. This is regardless of how many items are joined from the other side.