B+ Tree Routines
Insert
may need to create new root page (leaf page), use MINIBASE_BM->newpage(...) to allocate (remember newpage pins page so don’t forget to unpin)
also may allocate new page if you propagate up to root
should pin/unpin pages as you move up/down tree
Delete, new_scan
may want to factor commonality (looking for value to delete/start run)
new_scan
need mechanism for tracking current scan info (attach to index), need only have one scan per index