this is my initial thought about database index using b tree , this is not as typical as how database index works but it is intial step to dig more deep in that topic, i used b tree to index a column called id in table contain (id,name,age) by making the key contain the id and the page number that belong to it

just a btree with insert method and helper function called "handle input" that take record from user and ensure when records in current file exeed a certain number it create a new file and insert to it with helper json file called "current_page.json" that keeps track the number of the current file and the number of records in it

and a text file called "node.txt" that help to persist the b tree by inserting to it the id and the page number and another helper function "handle_search" that take id and begin to search for it in the tree by its o(log n) advantage then if it exist take the page number and begin to extract all the record from it

incoming improvments 1/to use the myisam stratigy by compute the exact byte where the record start and reading only the needed blocks that contain the record instead of reading all the file

2/include delete method in the tree