The science of database management
The science of database management
An overview of data warehousing and OLAP technology
ACM SIGMOD Record
Improved query performance with variant indexes
SIGMOD '97 Proceedings of the 1997 ACM SIGMOD international conference on Management of data
Bitmap index design and evaluation
SIGMOD '98 Proceedings of the 1998 ACM SIGMOD international conference on Management of data
ACM Computing Surveys (CSUR)
SIGMOD '84 Proceedings of the 1984 ACM SIGMOD international conference on Management of data
B+ Tree Indexes with Hybrid Row Identifiers in Oracle 8i
Proceedings of the 17th International Conference on Data Engineering
Proceedings of the 2nd International Workshop on High Performance Transaction Systems
Oracle8i Index-Organized Table and Its Application to New Domains
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
Extensible Indexing: a Framework for Integrating Domain-Specific Indexing Schemes into Oracle8i
ICDE '00 Proceedings of the 16th International Conference on Data Engineering
Efficient and compact indexing structure for processing of spatial queries in line-based databases
Data & Knowledge Engineering
B-tries for disk-based string management
The VLDB Journal — The International Journal on Very Large Data Bases
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Any auxiliary structure, such as a bitmap or a B+-tree index, that refers to rows of a table stored as a primary B+-tree (e.g., tables with clustered index in Microsoft SQL Server, or index-organized tables in Oracle) by their physical addresses would require updates due to inherent volatility of those addresses. To address this problem, we propose a mapping mechanism that 1) introduces a single mapping table, with each row holding one key value from the primary B+-tree, as an intermediate structure between the primary B+-tree and the associated auxiliary structures, and 2) augments the primary B+-tree structure to include in each row the physical address of the corresponding mapping table row. The mapping table row addresses can then be used in the auxiliary structures to indirectly refer to the primary B+-tree rows. The two key benefits are: 1) the mapping table shields the auxiliary structures from the volatility of the primary B+-tree row addresses, and 2) the method allows reuse of existing conventional table mechanisms for supporting auxiliary structures on primary B+- trees.This paper presents the mapping mechanism, its possible application in supporting various auxiliary structures on primary B+-trees, and a case study describing its use for supporting bitmap indexes on index-organized tables in Oracle9i. The case study demonstrates that the proposed mapping mechanism allows us to reuse existing bitmap index technologies with minimal changes. It also includes a comparison between bitmap and non-bitmap (B+- tree) index performance on index-organized tables for both single-table queries and star queries. The analytical and experimental studies show that the method is storage efficient, and (despite the mapping table overhead) provides performance benefits that are similar to those provided by bitmap indexes implemented on conventional tables.