A Histogram Based Analytical Approximate Query Processing for Massive Data

2013 ◽  
Vol 411-414 ◽  
pp. 362-365 ◽  
Author(s):  
Yi Jun Wang ◽  
Han Hu Wang ◽  
Hui Li

In this paper, we study the characteristics of analytical query processing and proposed a histogram based approximate method for query processing over massive data. We implemented this approach into Hive system and evaluate it with Hive and BlinkDB cluster, the experimental results verified that our method is significantly fast than these existing techniques.

2021 ◽  
Vol 14 (8) ◽  
pp. 1365-1377
Author(s):  
Tiantian Liu ◽  
Huan Li ◽  
Hua Lu ◽  
Muhammad Aamir Cheema ◽  
Lidan Shou

Indoor venues accommodate many people who collectively form crowds. Such crowds in turn influence people's routing choices, e.g., people may prefer to avoid crowded rooms when walking from A to B. This paper studies two types of crowd-aware indoor path planning queries. The Indoor Crowd-Aware Fastest Path Query (FPQ) finds a path with the shortest travel time in the presence of crowds, whereas the Indoor Least Crowded Path Query (LCPQ) finds a path encountering the least objects en route. To process the queries, we design a unified framework with three major components. First, an indoor crowd model organizes indoor topology and captures object flows between rooms. Second, a time-evolving population estimator derives room populations for a future timestamp to support crowd-aware routing cost computations in query processing. Third, two exact and two approximate query processing algorithms process each type of query. All algorithms are based on graph traversal over the indoor crowd model and use the same search framework with different strategies of updating the populations during the search process. All proposals are evaluated experimentally on synthetic and real data. The experimental results demonstrate the efficiency and scalability of our framework and query processing algorithms.


2007 ◽  
Vol 19 (7) ◽  
pp. 919-933 ◽  
Author(s):  
Benjamin Arai ◽  
Gautam Das ◽  
Dimitrios Gunopulos ◽  
Vana Kalogeraki

Author(s):  
Kasun S. Perera ◽  
Martin Hahmann ◽  
Wolfgang Lehner ◽  
Torben Bach Pedersen ◽  
Christian Thomsen

2011 ◽  
pp. 2203-2217
Author(s):  
Qing Zhang

In this article we investigate how approximate query processing (AQP) can be used in medical multidatabase systems. We identify two areas where this estimation technique will be of use. First, approximate query processing can be used to preprocess medical record linking in the multidatabase. Second, approximate answers can be given for aggregate queries. In the case of multidatabase systems used to link health and health related data sources, preprocessing can be used to find records related to the same patient. This may be the first step in the linking strategy. If the aim is to gather aggregate statistics, then the approximate answers may be enough to provide the required answers. At least they may provide initial answers to encourage further investigation. This estimation may also be used for general query planning and optimization, important in multidatabase systems. In this article we propose two techniques for the estimation. These techniques enable synopses of component local databases to be precalculated and then used for obtaining approximate results for linking records and for aggregate queries. The synopses are constructed with restrictions on the storage space. We report on experiments which show that good approximate results can be obtained in a much shorter time than performing the exact query.


2021 ◽  
Vol 546 ◽  
pp. 1113-1134
Author(s):  
Meifan Zhang ◽  
Hongzhi Wang

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