title: Why default index in oracle is called B-tree but not B+tree?
body: <p>i have a question on Oracle default index, it is called B-tree,</p>
  <p>This is from Oracle Doc,</p>
  <pre><code>B-Tree Indexes
  B-trees, short for balanced trees, are the most common type of database index. A B-tree index is an 
  ordered list of values divided into ranges. By associating a key with a row or range of rows, B-trees 
  provide excellent retrieval performance for a wide range of queries, including exact match and range 
  searches.
  
  A B-tree index has two types of blocks: branch blocks for searching and leaf blocks that store 
  values. 
  </code></pre>
  <p>from that description, i feel it is more like B+tree, as for B+tree, only leaf node store date, the branch just store keys pointing to leaf nodes,</p>
  <p>then why it is stated the default index for Oracle is B-tree but not B+tree?</p>