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From Stefan Guggisberg <stefan.guggisb...@gmail.com>
Subject Re: Jackrabbit Reference Lookup
Date Fri, 06 May 2011 15:23:27 GMT
On Thu, May 5, 2011 at 7:02 PM, kazim_ssuet@yahoo.com
<kazim_ssuet@yahoo.com> wrote:
>
> Stefan Guggisberg wrote:
>>
>> yes. references are stored on the target. for every mix:referenceable node
>> currently being referenced by 1-n reference properties there's one record
>> in the REFS table. that record stores the collection of property id's
>> refering to the corresponding mix:referenceable node.
>>
>
> So if I use weak references, would there be a seperate record for the
> reference? in REFS or any other table?

no.

> I understand that referential integrity will not be enforced in that case.

correct.

>
>
> Stefan Guggisberg wrote:
>>
>> both forward and reverse lookups are highly efficient.
>>
>
> Can you explain how forward lookup is done when there is no pointer to
> referenced node in referencing node data? Only way I can think of is to
> triverse all rows in REFS table along with their blob untill you find
> referencing node id in the blob.

i can't follow you here.

forward lookup => referenceProperty.getNode()

the internal value of a refererence property *is* the
unique identifier of the target node, i.e. the target
node is *directly* accessed using its unique identifier.

>
>
> Stefan Guggisberg wrote:
>>
>> the drawback of this approach is limited scalability. 10k and more
>> references to any particular node slow down write performance, i.e. adding
>> an additional reference to a target node already being referenced by lets
>> say 100k properties is relatively slow since the the entire collection of
>> referer id's needs to be stored.
>>
>
> I suppose this will not be an issue with weak references, assuming there is
> no record of reference in REFS or any other table. Am I right?

yes.

cheers
stefan

>
> Thanks,
> KS
>
> --
> View this message in context: http://jackrabbit.510166.n4.nabble.com/Jackrabbit-Reference-Lookup-tp3494206p3498886.html
> Sent from the Jackrabbit - Users mailing list archive at Nabble.com.
>

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