Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 14 Issue 3, Sept. 1989

Cactis: a self-adaptive, concurrent implementation of an object-oriented database management system
Scott E. Hudson, Roger King
Pages: 291-321
DOI: 10.1145/68012.68013
Cactis is an object-oriented, multiuser DBMS developed at the University of Colorado. The system supports functionally-defined data and uses techniques based on attributed graphs to optimize the maintenance of functionally-defined data. The...

Automatic verification of database transaction safety
Tim Sheard, David Stemple
Pages: 322-368
DOI: 10.1145/68012.68014
Maintaining the integrity of databases is one of the promises of database management systems. This includes assuring that integrity constraints are invariants of database transactions. This is very difficult to accomplish efficiently in the...

Updating derived relations: detecting irrelevant and autonomously computable updates
José A. Blakeley, Neil Coburn, Per-:1Vke Larson
Pages: 369-400
DOI: 10.1145/68012.68015
Consider a database containing not only base relations but also stored derived relations (also called materialized or concrete views). When a base relation is updated, it may also be necessary to update some of the derived relations. This paper...

Index scans using a finite LRU buffer: a validated I/O model
Lothar F. Mackert, Guy M. Lohman
Pages: 401-424
DOI: 10.1145/68012.68016
Indexes are commonly employed to retrieve a portion of a file or to retrieve its records in a particular order. An accurate performance model of indexes is essential to the design, analysis, and tuning of file management and database systems,...

Performance of a two-headed disk system when serving database queries under the scan policy
Y. Manolopoulos, J. G. Kollias
Pages: 425-442
DOI: 10.1145/68012.68017
Disk drives with movable two-headed arms are now commercially available. The two heads are separated by a fixed number of cylinders. A major problem for optimizing disk head movement, when answering database requests, is the specification of the...