A B+ tree is a self-balancing search tree where all data is stored in leaf nodes linked together. It has a maximum of order - 1 keys and order children per node, and performs searches by doing a binary search through the tree to find an exact match or return not found. An example shows a B+ tree of order 4 with 12 inserted elements and a search for 25.

1. B+ TREE
S E A RCHING

2. RULES:
• Maximum keys = order – 1
• Minimum keys = ceiling value (order/2) -1
• Maximum children = order
• Minimum children = ceiling value (order/2)
• All elements should be inserted at leaf node.
• Leaf nodes are also linked to each other.
• Note: All the elements are present at leaf node. All the intermediate nodes
are just the index to the elements present at leaf node.

3. ALGORITHM
• In B+ Tree, a search is one of the easiest procedures to execute and get fast and
accurate results from it.
• The following search algorithm is applicable:
• To find the required record, you need to execute the binary search on the available
records in the Tree.
• In case of an exact match with the search key, the corresponding record is returned
to the user.
• In case the exact key is not located by the search in the parent, current, or leaf
node, then a "not found message" is displayed to the user.
• The search process can be re-run for better and more accurate results.

4. B+ TREE OF ORDER 4:
Elements inserted: 1,4,7,10,17,21,31,25,19,20,28,42

5. SEARCH 25