Topic
Boolean conjunctive query
About: Boolean conjunctive query is a research topic. Over the lifetime, 1832 publications have been published within this topic receiving 64939 citations.
Papers published on a yearly basis
Papers
14 Jun 2020
TL;DR: In this paper, the authors give several novel results on the hardness of the resilience problem for conjunctive queries with self-joins, and present a dichotomy result for the class of single-self-join binary queries with exactly two repeated relations occurring in the query.
Abstract: The resilience of a Boolean query on a database is the minimum number of tuples that need to be deleted from the input tables in order to make the query false. A solution to this problem immediately translates into a solution for the more widely known problem of deletion propagation with source-side effects. In this paper, we give several novel results on the hardness of the resilience problem for conjunctive queries with self-joins, and, more specifically, we present a dichotomy result for the class of single-self-join binary queries with exactly two repeated relations occurring in the query. Unlike in the self-join free case, the concept of triad is not enough to fully characterize the complexity of resilience. We identify new structural properties, namely chains, confluences and permutations, which lead to various NP-hardness results. We also give novel involved reductions to network flow to show certain cases are in P. Although restricted, our results provide important insights into the problem of self-joins that we hope can help solve the general case of all conjunctive queries with self-joins in the future.
9 citations
TL;DR: A scalable solution based on CTEs with very promising empirical results centered on performance gains is provided, without costly hardware upgrades, that is capable of scaling with big datasets.
Abstract: We present a custom, Boolean query generator utilizing common-table expressions (CTEs) that is capable of scaling with big datasets. The generator maps user-defined Boolean queries, such as those interactively created in clinical-research and general-purpose healthcare tools, into SQL. We demonstrate the effectiveness of this generator by integrating our study into the Informatics for Integrating Biology and the Bedside (i2b2) query tool and show that it is capable of scaling. Our custom generator replaces and outperforms the default query generator found within the Clinical Research Chart cell of i2b2. In our experiments, 16 different types of i2b2 queries were identified by varying four constraints: date, frequency, exclusion criteria, and whether selected concepts occurred in the same encounter. We generated nontrivial, random Boolean queries based on these 16 types; the corresponding SQL queries produced by both generators were compared by execution times. The CTE-based solution significantly outperformed the default query generator and provided a much more consistent response time across all query types (M = 2.03, SD = 6.64 versus M = 75.82, SD = 238.88 s). Without costly hardware upgrades, we provide a scalable solution based on CTEs with very promising empirical results centered on performance gains. The evaluation methodology used for this provides a means of profiling clinical data warehouse performance.
9 citations
Journal Article•
9 citations
Patent•
29 Feb 2012TL;DR: In this article, the authors describe methods, systems, and apparatus that include receiving a sequence of one or more characters representing a first partial query entered into a search field on a computing device.
Abstract: Methods, systems, and apparatus are described that include receiving a sequence of one or more characters representing a first partial query entered into a search field on a computing device. A first list of query completions for the first partial query is provided for display on the computing device. One or more additional characters are then entered into the search field, where the sequence of characters and the additional characters cumulatively represent a second partial query. A second list of query completions are then obtained for the second partial query, and one or more query completions appearing in the first and the second lists are identified. Demotion scores for the identified query completions are then calculated which are used to demote the identified query completions to a lesser position within the second list, thereby forming a refined second list for display on the computing device.
8 citations
2 Nov 2009
TL;DR: This work proposes incorporating query views in a number of static pruning strategies, namely term-centric, document-centric and access-based approaches, which considerably outperform their counterparts for both disjunctive and conjunctive query processing in Web search engines.
Abstract: We propose incorporating query views in a number of static pruning strategies, namely term-centric, document-centric and access-based approaches. These query-view based strategies considerably outperform their counterparts for both disjunctive and conjunctive query processing in Web search engines.
8 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 5 |
| 2024 | 5 |
| 2023 | 12 |
| 2022 | 15 |
| 2021 | 10 |
| 2020 | 16 |