Philip Schmiegelt, B. Seeger, Andreas Behrend, W. Koch
Since navigation systems and tracking devices are becoming ubiquitous in our daily life, the development of efficient methods for processing massive sets of mobile objects are of utmost importance. Although future routes of mobile objects are often known in advance in many applications, this information is not fully utilized in most methods so far. In this paper, we reveal the beneficial effects of exploiting future routes for the early generation of the expected results of spatio-temporal queries. This kind of probable results is important for operative analytics in many applications like smart fleet management or intelligent logistics. For efficiently computing the high number of future trajectory points, a new index structure is presented which allows for a fast maintenance of query results under continuous changes of mobile objects. Our methods make use of specific update patterns, which require substantially less maintenance costs than the most general case of an update. A set of experiments based on a commonly used simulation environment shows the efficiency of our approach.
{"title":"Continuous queries on trajectories of moving objects","authors":"Philip Schmiegelt, B. Seeger, Andreas Behrend, W. Koch","doi":"10.1145/2351476.2351495","DOIUrl":"https://doi.org/10.1145/2351476.2351495","url":null,"abstract":"Since navigation systems and tracking devices are becoming ubiquitous in our daily life, the development of efficient methods for processing massive sets of mobile objects are of utmost importance. Although future routes of mobile objects are often known in advance in many applications, this information is not fully utilized in most methods so far. In this paper, we reveal the beneficial effects of exploiting future routes for the early generation of the expected results of spatio-temporal queries. This kind of probable results is important for operative analytics in many applications like smart fleet management or intelligent logistics. For efficiently computing the high number of future trajectory points, a new index structure is presented which allows for a fast maintenance of query results under continuous changes of mobile objects. Our methods make use of specific update patterns, which require substantially less maintenance costs than the most general case of an update. A set of experiments based on a commonly used simulation environment shows the efficiency of our approach.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"21 1","pages":"165-174"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73213962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luca Carafoli, F. Mandreoli, R. Martoglia, W. Penzo
In this paper we investigate the employment of different data reduction techniques to minimize V2I communication in an Intelligent Transportation System (ITS). We consider the context of the PEGASUS Project, where vehicles are equipped with sensor-based devices able to compute and communicate to a Control Centre (CC) information like vehicleăĂŹs position and speed. The CC relies on a general-purpose data management module that supports the execution of continuous queries as well as standard SQL one-time queries on the collected data to provide various infomobility services. The paper explores two categories of data reduction techniques: independent techniques, where vehicles autonomously send data to the CC, and information-need techniques, where data is sent by taking into account additional data received from the CC. The paper discusses and implements the technical changes needed in the CC to support the required infomobility services under the reduced availability of data. All the investigated techniques have been extensively evaluated in a variety of traffic scenarios.
{"title":"Evaluation of data reduction techniques for vehicle to infrastructure communication saving purposes","authors":"Luca Carafoli, F. Mandreoli, R. Martoglia, W. Penzo","doi":"10.1145/2351476.2351484","DOIUrl":"https://doi.org/10.1145/2351476.2351484","url":null,"abstract":"In this paper we investigate the employment of different data reduction techniques to minimize V2I communication in an Intelligent Transportation System (ITS). We consider the context of the PEGASUS Project, where vehicles are equipped with sensor-based devices able to compute and communicate to a Control Centre (CC) information like vehicleăĂŹs position and speed. The CC relies on a general-purpose data management module that supports the execution of continuous queries as well as standard SQL one-time queries on the collected data to provide various infomobility services.\u0000 The paper explores two categories of data reduction techniques: independent techniques, where vehicles autonomously send data to the CC, and information-need techniques, where data is sent by taking into account additional data received from the CC. The paper discusses and implements the technical changes needed in the CC to support the required infomobility services under the reduced availability of data. All the investigated techniques have been extensively evaluated in a variety of traffic scenarios.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"5 1","pages":"61-70"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87530009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
XML (Extensible Mark-up Language) is a well established format which is often used for modeling of semi-structured data. XPath and XQuery are de facto standards among XML query languages and searching for occurrences of a twig pattern query (TPQ) in an XML document is one of their core tasks. There is a large number of different approaches addressing the TPQ matching problem. The aim of this article is to compare the state-of-the-art techniques and give an overview which can help to understand the relationships between different methodologies used in this area. We distinguish three main areas of a TPQ processing: (1) index data structures and XML document partitioning, (2) join algorithms, and (3) cost-based optimizations. We cover the most important techniques in each area and explain their relationships and possible combinations.
{"title":"XML query processing: efficiency and optimality","authors":"Radim Bača, M. Krátký","doi":"10.1145/2351476.2351478","DOIUrl":"https://doi.org/10.1145/2351476.2351478","url":null,"abstract":"XML (Extensible Mark-up Language) is a well established format which is often used for modeling of semi-structured data. XPath and XQuery are de facto standards among XML query languages and searching for occurrences of a twig pattern query (TPQ) in an XML document is one of their core tasks.\u0000 There is a large number of different approaches addressing the TPQ matching problem. The aim of this article is to compare the state-of-the-art techniques and give an overview which can help to understand the relationships between different methodologies used in this area. We distinguish three main areas of a TPQ processing: (1) index data structures and XML document partitioning, (2) join algorithms, and (3) cost-based optimizations. We cover the most important techniques in each area and explain their relationships and possible combinations.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"4 1","pages":"8-13"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91081484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphs are popular data structures for modeling complex data types. There is a need for managing such graph data and providing efficient querying tools. In the graph mining realm, the problem lies in indexing a large number of graphs for fast retrieval. Indexing attributed graphs and using attributed queries can provide faster response time and results that are more refined. Our index technique ECTree focuses on extending an existing index to support attributed graph indexing and providing subgraph querying access to the extended index. The aim is to find a way such that the labels of the graphs as well as the attributes of the graphs are indexed at the same time. A query format is provided to query the extended index with flexibility on the attributes. In addition, regular expressions are used as query labels to provide flexibility. We also introduce a label-irrelevant vertex degree-attribute pruning method. All the techniques presented in our work are validated through experiments on both real and synthetic datasets.
{"title":"ECTree: an extended tree index for attributed subgraph queries","authors":"Jun Luo, G. Butler","doi":"10.1145/2351476.2351503","DOIUrl":"https://doi.org/10.1145/2351476.2351503","url":null,"abstract":"Graphs are popular data structures for modeling complex data types. There is a need for managing such graph data and providing efficient querying tools. In the graph mining realm, the problem lies in indexing a large number of graphs for fast retrieval. Indexing attributed graphs and using attributed queries can provide faster response time and results that are more refined.\u0000 Our index technique ECTree focuses on extending an existing index to support attributed graph indexing and providing subgraph querying access to the extended index. The aim is to find a way such that the labels of the graphs as well as the attributes of the graphs are indexed at the same time. A query format is provided to query the extended index with flexibility on the attributes. In addition, regular expressions are used as query labels to provide flexibility. We also introduce a label-irrelevant vertex degree-attribute pruning method. All the techniques presented in our work are validated through experiments on both real and synthetic datasets.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"102 1","pages":"216-221"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77372086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Object-relational databases (ORDB) can be created with a mixture of relational and object-oriented features, giving database designers a wide range of options. However, a poor combination of choices can result in problems with storing, retrieving or updating data. This paper shows that decisions about the features to use in ORDB design require a holistic approach, considering the database design as a whole and as part of an information system. We highlight problems that occur with some combinations of features that can cause poor functionality.
{"title":"ORDB holistic design","authors":"Patricia Roberts","doi":"10.1145/2351476.2351507","DOIUrl":"https://doi.org/10.1145/2351476.2351507","url":null,"abstract":"Object-relational databases (ORDB) can be created with a mixture of relational and object-oriented features, giving database designers a wide range of options. However, a poor combination of choices can result in problems with storing, retrieving or updating data. This paper shows that decisions about the features to use in ORDB design require a holistic approach, considering the database design as a whole and as part of an information system. We highlight problems that occur with some combinations of features that can cause poor functionality.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"24 1","pages":"239-242"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74448805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the distributed transactional database systems, there are a large number of concurrent transactions. Each transaction independently executes on a separate thread this is known as thread-to-transaction. The lock manager is hence responsible for maintaining isolation between concurrently-executing transactions, which takes more time from the total time of the execution. In this paper we present a system that improves the response time by using thread-to-metadata policy instead of using thread-to-transaction policy. The system consists of two modules: (a) Transaction Module, and (b) Data Module. The system minimizes the interaction with the lock manager and maintains all the ACID properties of the transactions. We also present experimental results that show how thread-to-metadata policy improves the response time.
{"title":"Transaction processing using thread-to-metadata","authors":"Hoda M. O. Mokhtar, Nariman Adel","doi":"10.1145/2351476.2351505","DOIUrl":"https://doi.org/10.1145/2351476.2351505","url":null,"abstract":"In the distributed transactional database systems, there are a large number of concurrent transactions. Each transaction independently executes on a separate thread this is known as thread-to-transaction. The lock manager is hence responsible for maintaining isolation between concurrently-executing transactions, which takes more time from the total time of the execution. In this paper we present a system that improves the response time by using thread-to-metadata policy instead of using thread-to-transaction policy. The system consists of two modules: (a) Transaction Module, and (b) Data Module. The system minimizes the interaction with the lock manager and maintains all the ACID properties of the transactions. We also present experimental results that show how thread-to-metadata policy improves the response time.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"93 1","pages":"230-234"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82399371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the most important metrics in measuring the performance of a database system is query response time, which is composed of I/O time and CPU time. I/O time is decided by the amount of data read/write from/to disks and how the data is located on disks. CPU time is decided by how the database system performs the query operations. So if we want to reduce the query response time we can reduce either I/O time or CPU time, or both of them. We know retrieving data from disks is much slower than retrieving data from main memory. Hence, one of the common ways to reduce I/O times is clustering data on disks so that queries will access only relevant data. This paper introduces an efficient algorithm, called AutoClust, for automatic database attribute clustering (or also called automatic database vertical partitioning) for single computers as well as cluster computers. It is based on closed item sets mined from queries and their attributes using association rule mining. The paper then presents experimental results comparing the performance of AutoClust with that of a baseline algorithm on both single computers and cluster computers using the TPC-H benchmark running on major commercial database systems. The experiments show that AutoClust has better query costs for both types of computers.
{"title":"Autonomous database partitioning using data mining on single computers and cluster computers","authors":"Liangzhe Li, L. Gruenwald","doi":"10.1145/2351476.2351481","DOIUrl":"https://doi.org/10.1145/2351476.2351481","url":null,"abstract":"One of the most important metrics in measuring the performance of a database system is query response time, which is composed of I/O time and CPU time. I/O time is decided by the amount of data read/write from/to disks and how the data is located on disks. CPU time is decided by how the database system performs the query operations. So if we want to reduce the query response time we can reduce either I/O time or CPU time, or both of them. We know retrieving data from disks is much slower than retrieving data from main memory. Hence, one of the common ways to reduce I/O times is clustering data on disks so that queries will access only relevant data. This paper introduces an efficient algorithm, called AutoClust, for automatic database attribute clustering (or also called automatic database vertical partitioning) for single computers as well as cluster computers. It is based on closed item sets mined from queries and their attributes using association rule mining. The paper then presents experimental results comparing the performance of AutoClust with that of a baseline algorithm on both single computers and cluster computers using the TPC-H benchmark running on major commercial database systems. The experiments show that AutoClust has better query costs for both types of computers.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"24 1","pages":"32-41"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88202331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eveline R. Sacramento, M. Casanova, K. Breitman, A. Furtado, J. Macêdo, V. Vidal
Data mashups constructed from independent sources may contain inconsistencies, puzzling the user that observes the data. This paper formalizes the notion of consistent data mashups and introduces a heuristic procedure to compute such mashups.
{"title":"Dealing with inconsistencies in linked data mashups","authors":"Eveline R. Sacramento, M. Casanova, K. Breitman, A. Furtado, J. Macêdo, V. Vidal","doi":"10.1145/2351476.2351496","DOIUrl":"https://doi.org/10.1145/2351476.2351496","url":null,"abstract":"Data mashups constructed from independent sources may contain inconsistencies, puzzling the user that observes the data. This paper formalizes the notion of consistent data mashups and introduces a heuristic procedure to compute such mashups.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"371 1","pages":"175-180"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77971421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
XML (eXtensible Markup Language) became in recent years the new standard for data representation and exchange on the WWW. This has resulted in a great need for data cleaning techniques in order to identify outlying data. In this paper, we present a technique for outlier detection that singles out anomalies with respect to a relevant group of objects. We exploit a suitable encoding of XML documents that are encoded as signals of fixed frequency that can be transformed using Fourier Transforms. Outliers are identified by simply looking at the signal spectra. The results show the effectiveness of our approach.
{"title":"XML class outlier detection","authors":"G. Manco, E. Masciari","doi":"10.1145/2351476.2351494","DOIUrl":"https://doi.org/10.1145/2351476.2351494","url":null,"abstract":"XML (eXtensible Markup Language) became in recent years the new standard for data representation and exchange on the WWW. This has resulted in a great need for data cleaning techniques in order to identify outlying data. In this paper, we present a technique for outlier detection that singles out anomalies with respect to a relevant group of objects. We exploit a suitable encoding of XML documents that are encoded as signals of fixed frequency that can be transformed using Fourier Transforms. Outliers are identified by simply looking at the signal spectra. The results show the effectiveness of our approach.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"77 1","pages":"155-164"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72707293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we introduce a method to infer a Schematron schema from a set of XML documents. We analyze different aspect of Schematron schema generation. Since the automatic inferring of XML documents is not a new problem, we will introduce only a single method that we will use in our experimental implementation. In the implementation we generate a grammar using the introduced inferring method and we allow the user to modify the grammar. The grammar is then transformed into Schematron schema by the use of our algorithm. Experimental results are a part of the paper.
{"title":"Schematron schema inference","authors":"M. Kozák, J. Stárka, I. Holubová","doi":"10.1145/2351476.2351482","DOIUrl":"https://doi.org/10.1145/2351476.2351482","url":null,"abstract":"In this paper we introduce a method to infer a Schematron schema from a set of XML documents. We analyze different aspect of Schematron schema generation. Since the automatic inferring of XML documents is not a new problem, we will introduce only a single method that we will use in our experimental implementation. In the implementation we generate a grammar using the introduced inferring method and we allow the user to modify the grammar. The grammar is then transformed into Schematron schema by the use of our algorithm. Experimental results are a part of the paper.","PeriodicalId":93615,"journal":{"name":"Proceedings. International Database Engineering and Applications Symposium","volume":"42 1","pages":"42-50"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86025088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：