Re: [rules-users] Will the alternative lead to a better performance?
Stephen,
As long as you use an "==" constraint as your example shows, the
first alternative will be more performatic. This is because drools
indexes facts based on your constraints. So, your first case will
require a single "==" comparison to find user name "A" and a single
comparison to find user name "B". Of course, if you have huge amound of
objects where hashcode for name start to clash, you may have more than
one comparison, but the effect is negligible when compared to all other
costs of having that many facts.
Second alternative works and will also hash object types, but it will
create a lot more infrastructure classes and Rete Nodes to deal with
your 500 different classes. So it is a worst alternative for the
proposed scenario.
[]s
Edson
Premkumar Stephen wrote:
Hi,
Consider that I have 500 instances of interface userI. Now, there are
3000 rules currently written based on a combination of these instances.
if {
$a : userI (name = "A")
$b : userI (name = "B")
}
then
{
//do some actions
}
How many tests are needed for a match in the RETE network for this rule?
If I created 500 classes, one for each object, such as UserA
implements userI and so on... my rule will look like:
if {
$a : UserA()
$b : UserB()
}
then
{
//do some actions
}
Will this lead to better performance since there will only be one such
instance of this object?
As for class-loading concerns, will there be a parsing/memory penalty
to be paid for having 500 classes now instead of one?
Thanks!
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Edson Tirelli
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