Re: [Springframework-developer] OT : Anyone know of a solution for storing (and retrieving) hierarchical data efficiently?

[Colin S. <col...@ex...>]

Of course LDAP is not transactional  (unless wrapped with some sort of=20
transactional wrapper, which I've never seen)...

Eduardo Issao Ito wrote:

>
> You can try using LDAP, it is well suited for hierarchical data, but=20
> it is not efficient when doing updates.
>
> Another alternative would be an XML database like dbXML or Xindice.=20
> It's much easier doing an XPath query than traversing a complex object=20
> hierarchy.
>
>
> Cameron Braid wrote:
>
>> I am implementing a system that needs to store a fair bit of=20
>> hierarchical data.
>>
>> =20
>>
>> For previous apps that have had this requirement, I stored the=20
>> hierarchy in relational databases, which worked sufficiently well.
>>
>> =20
>>
>> BUT, this new application has a lot of operations that deal with deep=20
>> and wide directed trees (I don=92t know if that is the correct name fo=
r=20
>> them, but I am sure you get the picture).
>>
>> =20
>>
>> This would require a LOT of trips to the database to fetch the=20
>> children each time a transaction runs.
>>
>> =20
>>
>> I could try and implement this using some complex caches but I though=20
>> I would see if anyone else has an alternate solution.
>>
>> =20
>>
>> It will need to be able to participate in a distributed transaction,=20
>> since some data will be stored in a relational database, and some in=20
>> the hierarchy store.
>>
>> =20
>>
>> I have thought of products like
>>
>> =20
>>
>>     * Prevayler http://www.prevayler.org <http://www.prevayler.org/>
>>           o seems a little amateur from the wiki
>>           o seems to support transactions
>>           o needs to keep all data in memory =96 which probably won=92=
t work
>>             for this site
>>           o doesn=92t seem to support JTA
>>     * Berkeley DB Java Edition -=20
>> http://www.sleepycat.com/products/je.shtml
>>           o Supports transactions
>>           o doesn=92t seem to support JTA
>>           o may be too low level
>>     * JDBM http://jdbm.sourceforge.net/
>>           o Simple transactional persistent hash map implementation
>>
>> =20
>>
>> Does anyone have any suggestions on other =91preferably=92 open source=
=20
>> products, or techniques to achieve wish to do.
>>
>> =20
>>
>> I am also very new to XA and distributed transactions, so if anyone=20
>> has any hints on using XA with spring please show me where I can find=20
>> some resources.
>>
>> =20
>>
>> Also - it is possible to implement XA support for systems like jdbm,=20
>> prevayler or Berkley db ?
>