[rules-users] Is there a faster way of doing this in Drools ?

[soumya_sd]

Vincent Legendre wrote
> 
> And I did not see all pending posts ...
> 
> By reading them, there is another fact that lead to "don't use drools".
> You said that you query a distant DB. So, if you write rules to filter
> your data, you will have first to get ALL data from your distant DB, add
> ALL data in the drools WM, and only then fire rules on them to filter the
> data and get only a subset of them.
> 
> To me (my opinion), it is an anti-pattern. Filtering a large amount of
> data and return only a subset of them is the database job.
>  

The filtering options provided by the remote databases (most of them are
exposed as REST APIs) are "limited". I uses these options whenever I can to
filter data at the source. However, sometimes it's not possible to filter
everything at the source. In such cases I don't have any other option but to
get all the data and then apply my filters "locally." 


Vincent Legendre wrote
> 
> 
> Oh, yes, you intend to do complex rules that cannot be set as SQL like
> syntax ... 
> You should think of cutting you system in two, by making each tool doing
> what it is designed for :
>    - use SQL like for basic filtering, by sending the query to the distant
> DB and thus getting ONLY the data needed
>    - make drools running of this subset of data to implement more complex
> things
> 
> 

Now as discussed below, I can apply "simple" filters by using a in-memory
database (or inserting the data into a SQL database and then using SQL
queries) OR load everything into a WM and then apply these "dynamic" rules. 

I think both approaches can work, I just need to figure out the tradeoffs. 

Thanks again ! 




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