Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 14 Issue 4, Dec. 1989

Imprecise schema: a rationale for relations with embedded subrelations
Howard M. Dreizen, Shi-Kuo Chang
Pages: 447-479
DOI: 10.1145/76902.76903
Exceptional conditions are anomalous data which meet the intent of a schema but not the schema definition, represent a small proportion of the database extension, and may become known only after the schema is in use. Admission...

Integrity = validity + completeness
Amihai Motro
Pages: 480-502
DOI: 10.1145/76902.76904
Database integrity has two complementary components: validity, which guarantees that all false information is excluded from the database, and completeness, which guarantees that all true information is included...

Using semantic knowledge of transactions to increase concurrency
Abdel Aziz Farrag, M. Tamer Özsu
Pages: 503-525
DOI: 10.1145/76902.76905
When the only information available about transactions is syntactic information, serializability is the main correctness criterion for concurrency control. Serializability requires that the execution of each transaction must appear to every...

Query processing techniques in the summary-table-by-example database query language
Gultekin Özsoyoğlu, Victor Matos, Meral Özsoyoğlu
Pages: 526-573
DOI: 10.1145/76902.76906
Summary-Table-by-Example (STBE) is a graphical language suitable for statistical database applications. STBE queries have a hierarchical subquery structure and manipulate summary tables and relations with set-valued attributes. The...

On the effect of join operations on relation sizes
Danièle Grady, Claude Puech
Pages: 574-603
DOI: 10.1145/76902.76907
We propose a generating function approach to the problem of evaluating the sizes of derived relations in a relational database framework. We present a model of relations and show how to use it to deduce probabilistic estimations of derived...

A unified analysis of batched searching of sequential and tree-structured files
Sheau-Dong Lang, James R. Driscoll, Jiann H. Jou
Pages: 604-618
DOI: 10.1145/76902.76908
A direct and unified approach is used to analyze the efficiency of batched searching of sequential and tree-structured files. The analysis is applicable to arbitrary search distributions, and closed-form expressions are obtained for the expected...