[development] The new menu system

[karoly at negyesi.net]

> Is the number of items in "generated list of possible options" -- that is, the 
> SQL IN LIST small?  Is "path" an indexed column?  Doing select statements with 
> IN lists is often quite inefficient.


For n pieces of URL parts, it's 2^n - 1. We cut at six, so it's maximum is 63. 

Here it is for three pieces:

node/12/edit
node/12/%
node/%/edit
node/%/%
node/12
node/%
node

this is seven. Whether path is an indexed column or not is not a question at this point. It's more like an assert: path must be indexed.
 
> Is the expected result set a single item, a few items or a lot of items?  (The 
> answer is probably evident from an understanding of just exactly how this menu 
> scheme works, but I admit I have not quite grasped it completely yet.)

One item. Everything is packed into that item by the builder. At some point I thought you will have three items, then approximately n items or less (depending on how many children you have). But then came the BarCamp menu talk and now everything is in the builder.
 
> Unserializing a massive tree is certainly slow.  Let's be sure we don't shoot 
> ourselves in the foot with an algorithm which may be subject to SQL end-cases 
> that take forever to retrieve.  :-)

Let's hope not. We are trying to make it as fast as possible.

Currently, I work on the builder, to build an array out of depths and weights, use array_multisort and then vancode the stuff so that the navigation block is in correct order.

Regards

NK