NDLI: Online reorganization of databases

Content Provider	ACM Digital Library
Author	Sockut, Gary H. Iyer, Balakrishna R.
Copyright Year	2009
Abstract	In practice, any database management system sometimes needs reorganization, that is, a change in some aspect of the logical and/or physical arrangement of a database. In traditional practice, many types of reorganization have required denying access to a database (taking the database offline) during reorganization. Taking a database offline can be unacceptable for a highly available (24-hour) database, for example, a database serving electronic commerce or armed forces, or for a very large database. A solution is to reorganize online (concurrently with usage of the database, incrementally during users' activities, or interpretively). This article is a tutorial and survey on requirements, issues, and strategies for online reorganization. It analyzes the issues and then presents the strategies, which use the issues. The issues, most of which involve design trade-offs, include use of partitions, the locus of control for the process that reorganizes (a background process or users' activities), reorganization by copying to newly allocated storage (as opposed to reorganizing in place), use of differential files, references to data that has moved, performance, and activation of reorganization. The article surveys online strategies in three categories of reorganization. The first category, maintenance, involves restoring the physical arrangement of data instances without changing the database definition. This category includes restoration of clustering, reorganization of an index, rebalancing of parallel or distributed data, garbage collection for persistent storage, and cleaning (reclamation of space) in a log-structured file system. The second category involves changing the physical database definition; topics include construction of indexes, conversion between $B^{+}$ -trees and linear hash files, and redefinition (e.g., splitting) of partitions. The third category involves changing the logical database definition. Some examples are changing a column's data type, changing the inheritance hierarchy of object classes, and changing a relationship from one-to-many to many-to-many. The survey encompasses both research and commercial implementations, and this article points out several open research topics. As highly available or very large databases continue to become more common and more important in the world economy, the importance of online reorganization is likely to continue growing.
Starting Page	1
Ending Page	136
Page Count	136
File Format	PDF
ISSN	03600300
e-ISSN	15577341
DOI	10.1145/1541880.1541881
Journal	ACM Computing Surveys (CSUR)
Volume Number	41
Issue Number	3
Language	English
Publisher	Association for Computing Machinery (ACM)
Publisher Date	2009-07-01
Publisher Place	New York
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Clustering Concurrent reorganization Indexes Log-structured file systems Maintenance Online reorganization Redefinition Reorganization Restructuring Schema evolution Very large databases
Content Type	Text
Resource Type	Article
Subject	Theoretical Computer Science Computer Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Performance analysis of a concurrent file reorganization algorithm for record clustering

Incremental maintenance of schema-restructuring views in SchemaSQL

Swarm Intelligence Based File Replication and Consistency Maintenance in Structured P2P File Sharing Systems

Large-scale file systems with the flexibility of databases

Concurrent file reorganization for record clustering: a performance study

Multilevel extendible hashing: a file structure for very large databases

Implementation of a Linux log-structured file system with a garbage collector

Energy-aware reorganization in log-structured file systems (1978).

Serverless network file systems

Online reorganization of databases

Similar Documents

Performance analysis of a concurrent file reorganization algorithm for record clustering

Incremental maintenance of schema-restructuring views in SchemaSQL

Swarm Intelligence Based File Replication and Consistency Maintenance in Structured P2P File Sharing Systems

Large-scale file systems with the flexibility of databases

Concurrent file reorganization for record clustering: a performance study

Multilevel extendible hashing: a file structure for very large databases

Implementation of a Linux log-structured file system with a garbage collector

Energy-aware reorganization in log-structured file systems (1978).

Serverless network file systems

Online reorganization of databases