Oracle International Corporation

Charles G Freiwald

Jagannathan Srinivasan

Aravind Yalamanchi

Souripriya Das

Eugene Inseok Chong

Ramkumar Krishnan

Mahesh Jagannath

Anh-Tuan Tran

A system for organizing and accessing a database. The system includes a primary B+tree index, a secondary B+tree index, a plurality of mapping table row identifiers stored in the secondary B+tree index and a plurality of database addresses for leaf blocks of the primary B+tree index corresponding to mapping table rows.

Supporting B+tree indexes on primary B+tree structures with large primary keys

A mapping mechanism for a primary B+tree in a database management system. The primary B+tree includes a plurality of rows. The mapping mechanism includes introducing a mapping table that includes a plurality of rows, including a row for each row of the primary B+tree, and that stores the logical identifier of the corresponding primary B+tree row. In addition, reverse mapping is provided by augmenting a primary B+tree to include in each primary B+tree row a physical row identifier of the corresponding mapping table row. An auxiliary structure created on a primary B+tree can make use of the proposed mapping mechanism. Specifically, the auxiliary structures refers to primary B+tree rows indirectly by storing the physical row identifier of the corresponding mapping table row.

Mapping logical row identifiers for primary B+tree-like structures to physical row identifiers

A method for building bitmap indexes on a primary B&plus;tree used for storing data in the database that has a mapping table associated with it. The bitmap index is built by using the mapping table row identifiers.

Supporting bitmap indexes on primary B&plus;tree like structures

A system for organizing and accessing a database. The system includes a primary B&plus;tree index, a secondary B&plus;tree index, a plurality of mapping table row identifiers stored in the secondary B&plus;tree index and a plurality of database addresses for leaf blocks of the primary B&plus;tree index corresponding to mapping table rows.

Supporting B&plus;tree indexes on primary B&plus;tree structures with large primary keys

A database system having logical row identifiers (rowids) includes a secondary index which is traversed to locate a secondary index entry that includes a target secondary key value. Each secondary index entry also includes a logical rowid element. Each logical rowid element has both a primary key value element, and a datablock address element identifying a leaf block in an index-organized table that likely includes a row corresponding to the primary key value element. The leaf block is scanned to locate the row in the index-organized table that includes the target secondary key value and corresponds with the located, secondary index entry. A primary key scan is performed on the index-organized table if the row in the index-organized table is not located in the identified datablock.

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Amherst, NH, United States of America

Charles G Freiwald