Expert Oracle Indexing and Access Paths: Maximum Performance for Your Database

© Darl Kuhn, Sam R. Alapati and Bill Padfield 2016

Darl Kuhn, Sam R Alapati and Bill Padfield, Expert Oracle Indexing and Access Paths, 10.1007/978-1-4842-1984-3_2

2. B-tree Indexes

Darl Kuhn¹ , Sam R. Alapati² and Bill Padfield³

(1)Morrison, Colorado, USA

(2)Flower Mound, Texas, USA

(3)Aurora, Colorado, USA

The B-tree index is the default index type in Oracle. This index type is known as B-tree because the table row identifier (ROWID) and associated column values are stored within index blocks in a balanced tree-like structure. Oracle B-tree indexes are used for the following reasons:

• Improving SQL statement performance

• Enforcing uniqueness of primary key and unique key constraints

• Reducing potential locking issues with parent and child table tables ...