DocumentCode :
1122749
Title :
Function materialization in object bases: design, realization, and evaluation
Author :
Kemper, Alfons ; Kilger, Christoph ; Moerkotte, Guido
Volume :
6
Issue :
4
fYear :
1994
fDate :
8/1/1994 12:00:00 AM
Firstpage :
587
Lastpage :
608
Abstract :
View materialization is a well-known optimization technique of relational database systems. We present a similar, yet more powerful, optimization concept for object-oriented data models: function materialization. Exploiting the object-oriented paradigm-namely, classification, object identity, and encapsulation-facilitates a rather easy incorporation of function materialization into (existing) object-oriented systems. Only those types (classes) whose instances are involved in some materialization are appropriately modified and recompiled, thus leaving the remainder of the object system invariant. Furthermore, the exploitation of encapsulation (information hiding) and object identity provides for additional performance tuning measures that drastically decrease the invalidation and rematerialization overhead incurred by updates in the object base. First, it allows us to cleanly separate the object instances that are irrelevant for the materialized functions from those that are involved in the materialization of some function result, and this to penalize only those involved objects upon update. Second, the principle of information hiding facilitates fine-grained control over the invalidation of precomputed results. Based on specifications given by the data type implementor, the system can exploit operational semantics to better distinguish between update operations that invalidate a materialized result and those that require no rematerialization. The paper concludes with a quantitative analysis of function materialization based on two sample performance benchmarks obtained from our experimental object base system GOM
Keywords :
data encapsulation; database theory; object-oriented databases; optimisation; query processing; GOM; access methods; classification; data type implementor; database programming languages; encapsulation; fine-grained control; function materialization; indexing methods; information hiding; object bases; object identity; object-oriented data models; object-oriented languages; operational semantics; optimization technique; performance tuning measures; query processing; relational database systems; rematerialization; updates; view materialization; Data engineering; Data models; Database systems; Design optimization; Encapsulation; Indexing; Object oriented databases; Performance analysis; Query processing; Relational databases;
fLanguage :
English
Journal_Title :
Knowledge and Data Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
1041-4347
Type :
jour
DOI :
10.1109/69.298175
Filename :
298175
Link To Document :
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