[TYPO3-dev] Typo3 Performance

[R. van Twisk]

Dmitry Dulepov wrote:
> Hi!
>
> Martin Kutschker wrote:
>   
>> Can you explain this model in short or give me a pointer to an online 
>> resource?
>>     
>
> This model was proposed by Oracle DB expert Joe Celko. Generally it 
> marks branches of the tree with consecutive numbers so that when you 
> want to fetch root path or get the whole branch, you just need to issue 
> query with two numbers. Example:
>
>                      |- C (3,4)
>          |- B (2, 7)-|
> A(1,14)-|           |- D (5,6)
>          |           |
>          |- E (8,13)-|- F (9,10)
>                      |
>                      |- G (11,12)
>
> For example, to get a root line of F, exec this simple sql:
>
> select t2.uid from table t2, table t1 where t1.num1 between t2.num1 and 
> t2.num2 and t1.num1=9
>
> Here num1 is the first number (i.e. 1 for A) and num2 is the second (14 
> for A).
>
> That's all. Now imagine if you have index that consists from 
> (uid,num1,num2)...
>
> Celko's article:
> http://www.intelligententerprise.com/001020/celko.jhtml?_requestid=235427
>
>   
I happen to have a simple function that can can update the nested set 
model from the
adjacency tree model.

So we can use the current methods and simply add the left/right nodes to 
the tree.

The above version of the nested set model is resource expensive when 
nodes are added/removed.

There is also a 'gap' version which reserves space to add nodes without 
adding
a lot of overhead to updating the whole nested set.


Currently my function simply updates the whole tree when a change is made,
I could easily change it and hook it into TCEMain and add a left/right 
node to the page tree.

When pages are only moved around from the BE I think it still will work 
'ok' but
not effectively up until a couple of 1000 pages.

I have one site with 2000 pages, I could try it on there how long a 
update would take.



Ries