Reading Filepro Index

[Kenneth Brody]

On 11/1/2010 5:32 PM, Cindy Youngman wrote:
[...]
> https://www.fptech.com/Products/Docs/FPFormat/autoix45.shtml#sort
>
> First off, I dont understand what a freechain is.

Just like the freechain within the key file is a linked list of free records 
in the filePro file, the freechain in the index is a linked list of 
available nodes within the index file.

> Then I am unsure of how to interpret the nodes.
>
> What does the left pointer point to on the non-leaf-nodes? Is it pointing to the parent?

No.  It points to the left-most child.

> And all other pointers are pointing to children nodes? Id assume that a non-leaf-node would only contain at most, one other non-leaf-node and any amount of leaf nodes?

Non-leaf nodes point to their children.  Leaf nodes have no children.

> Leaf nodes contain the data. I get that.  Backwards pointer points to the parent node.

No, the leaf node's "backwards node pointer" points to the leaf node that is 
immediately before it.

> Forwards pointer possibly points to other leaf-nodes with a duplicate key?

The leaf node's "forward node pointer" points to the leaf node that is 
immediately after it.  (Perhaps "previous" and "next" would be a better 
choice of words?)

Together, they make a doubly-linked list of leaf nodes.

> Am I understanding this right? If so, what the heck are free chains?

See above.

[...]

-- 
Kenneth Brody