Hi,

We need to generate drl file from a template. Since the format of the rules parameters doesn’t fall very well within decision table concept (the parameters are not ‘homogeneous’, so each row in the input excel table can mean different things), we decided to define the rules by automatically generating drl files from a set of templates. To cover more cases with a single template we’d need to bind every field of column by default, even if the binding would not be used.

For example (Freemarker syntax is used in the template below):

Rule ${ruleId}

            When

                        Record ( $account : account ${operation}    ${value} )

                        ….

            Then

                        …..

End

In the example above, ‘operation’, ‘value’ and ‘ruleId’ are objects in the data model that we merge with the template. One case of the rule would be when both ‘operation’ and ‘value’ are empty strings. This will result in this LHS:   Record ( $account : account ). Another case might be when ‘operation’ is ‘==’ string and ‘value’ is ‘1’:   Record ( $account : account == 1 ).

The above is a simplified template to demonstrate the point. The real business data model for facts (Record object) would have around 10 fields and we can have ~ 5 to 10 columns per rule. I wonder what kind of performance implications does field binding bring? Are there any or this is being optimized / filtered out by some preprocessor?

In other words, is there significant difference in performance for the following LHS expressions:

1) Record ( $account : account,  $name : name == ‘xxx’,   $balance : balance > 100, ….)

Vs

2) Record (name == ‘xxx’,  balance > 100, ….)

Providing the functionality of both of these LHS expressions is the same and field bindings in LHS #1 are never used throughout the rule.

Thanks,

Vlad