[rules-users] Re: Drools indexing

[Mark Proctor]

Senlin Liang wrote:
> Thanks Mark!
>
> I got another question: what kind of indexing is used in drools? what
> field does it index?
>   
It wil index the field used in the constraint
Person( name == "mark" )
Person( name == $var )

Both of those pattners will be indexed no the name field, the first is 
what we call alpha node hashing, as it's on a literal and the latter is 
join node index on the name field.
> I checked the online manual, it seems that I uses hashing index, but i
> am not sure the details.
>
> The reason that I am asking this question is that: drools runs really
> faster for one of my program. In this program, there is information
> about DBLP publications:
>    a(primary key, property, values), where primary key is the primary
> key of one publication, property can be one of "author, year, ...",
> and value is the value of the property. I run the query by joining the
> tables together using the primary key. Drools runs really fast for
> this program.
>
> I am wondering whether there is anything behind to make drools fast.
> Senlin
>
> On Wed, Oct 15, 2008 at 3:41 PM, Mark Proctor <mproctor at codehaus.org> wrote:
>   
>> Senlin Liang wrote:
>>
>> One more question: does drools index intermediate results (such as the
>> inserted objects in actions)?
>>
>>
>> Any inserted object used in == constraints is indexed for that constraint.
>>
>> Is there any cost-based optimization for queries?
>>
>>
>> no
>>
>> Thanks
>>
>> On Wed, Oct 15, 2008 at 9:10 AM, Senlin Liang <senlin.liang at gmail.com>
>> wrote:
>>
>>
>> Hi all,
>>
>> I got one question: How does drools index the objects in memory? Does
>> it use hashing index, based on what? Or drools uses adaptive indexing?
>>
>> Thanks a lot,
>> Senlin
>>
>>
>>
>>
>>
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>>
>>     
>
>
>
>   

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