Reading Filepro Index

[Cindy Youngman]

A collegue of mine posted this question to the forums a few days ago and did not receive any response so I'm hoping someone here may be able to answer.  Thanks in advance.

Hey all. Long story short I am working on a project to build a bridge between php and filepro. I have a series of classes which allow me to grab  the data from a specific record based on key or number. I can also grab all records in the database, but this is problematic on remotely large dbs.

So I figure I can use the index files to be able to quickly determine what records I need to grab and then grab those records, allowing me real time access to filepro data. I am looking at the documentation on the index files and have some questions.

https://www.fptech.com/Products/Docs/FPFormat/autoix45.shtml#sort

First off, I dont understand what a freechain is.

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? 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?

Leaf nodes contain the data. I get that.  Backwards pointer points to the parent node. Forwards pointer possibly points to other leaf-nodes with a duplicate key?

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

Any help would be great.


Cindy Youngman
Software Developer
Luna Carpet
cyoungman at sc.rr.com  or cyoungman at luna.com
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