Hierarchical Data Storage

[Ruslan Zasukhin]

On 11/2/07 10:09 PM, "Bart Pietercil" <bart.pietercil at gmail.com> wrote:

>> ---------
>> Another good point here.
>> 
>> Even if you self will implement preorder tree on Valentina 2.5.5
>> You will get much faster speed of updates
>> 
>>     UPDATE ...  Left = left + 2
>> 
>> Because this is operation on separate column, and Valentina keep
>> fields by
>> columns, so you win > N times (when N is number of fields in table).
> 
> 
> So for this Valentina (2.5.5) I basically implement a flat table T1
> like this
 
> T1(rec_id 'automatic', values_i_need_in_the_table, leftfield,rightfield)


------------ 
> There is probably something to be gained if I am to introduce already
> a binary link (self join) in order to have an easy acces to the
> direct children of a certain item without needing to go through the
> whole stack. It looks like we would end up with a mixed model then.

actually find direct children is as easy as

    WHERE parentPtr = somevalue


> Recursive model (without recursion because we only use it for level n
> + 1) +  preorder tree traversal for links that are going deeper than
> level n +1




-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]