Oracle International Corporation

Ramkumar Krishnan

Jagannathan Srinivasan

Aravind Yalamanchi

Souripriya Das

Eugene Inseok Chong

Charles G Freiwald

Joyo Wijaya

Susan M Kotsovolos

Rajagopalan Govindarajan

Anh-Tuan Tran

Mahesh Jagannath

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 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.

Database system having logical row identifiers

A method, system and computer-readable medium is provided for grouping database objects into logical groupings in order to simplify administrative and other operations that need to be performed by the database server. Such operations can be performed once at the logical group level for a group of related objects, as opposed to at the individual database object level. For increased flexibility, the logical groupings need not dictate the format, schema or location of their members. A hierarchy may be established between the logical groupings, where child groupings inherit some or all of the properties of the parent groupings. A correspondence may be established between some groupings and operating system directories, allowing identifiers associated with the groupings to be used as aliases for the full operating system paths to the corresponding directories.

Logical groupings within a database

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Nashua, NH, United States of America

Ramkumar Krishnan