Oracle Bitmap Indexes Explained

In Oracle, a bitmap index is a special type of index used to speed up queries on columns with low cardinality (meaning a limited number of unique values). This type of index maps column values to bitmaps and uses bitwise operations to quickly locate rows that contain specific values. Bitmap indexes are suitable for columns with relatively even data distribution and can significantly improve performance when using equality conditions in queries. They are typically used in OLAP scenarios and not suitable for OLTP scenarios.