International Workshop on Data Warehousing and OLAP最新文献_第10页

Solving summarizability problems in fact-dimension relationships for multidimensional models 解决多维模型中事实-维度关系的总结性问题

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458443

J. Mazón, Jens Lechtenbörger, J. Trujillo

{"title":"Solving summarizability problems in fact-dimension relationships for multidimensional models","authors":"J. Mazón, Jens Lechtenbörger, J. Trujillo","doi":"10.1145/1458432.1458443","DOIUrl":"https://doi.org/10.1145/1458432.1458443","url":null,"abstract":"Multidimensional analysis allows decision makers to efficiently and effectively use data analysis tools, which mainly depend on multidimensional (MD) structures of a data warehouse such as facts and dimension hierarchies to explore the information and aggregate it at different levels of detail in an accurate way. A conceptual model of such MD structures serves as abstract basis of the subsequent implementation according to one specific technology. However, there is a semantic gap between a conceptual model and its implementation which complicates an adequate treatment of summarizability issues, which in turn may lead to erroneous results of data analysis tools and cause the failure of the whole data warehouse project. To bridge this gap for relationships between facts and dimension, we present an approach at the conceptual level for (i) identifying problematic situations in fact-dimension relationships, (ii) defining these relationships in a conceptual MD model, and (iii) applying a normalization process to transform this conceptual MD model into a summarizability-compliant model that avoids erroneous analysis of data. Furthermore, we also describe our Eclipsebased implementation of this normalization process.","PeriodicalId":335396,"journal":{"name":"International Workshop on Data Warehousing and OLAP","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122958959","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}

引用次数: 29

A framework for recommending OLAP queries 推荐OLAP查询的框架

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458446

A. Giacometti, Patrick Marcel, E. Negre

引用次数: 66

Transaction reordering with application to synchronized scans 事务重新排序与应用程序同步扫描

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458436

Gang Luo, J. Naughton, Curt J. Ellmann, M. Watzke

{"title":"Transaction reordering with application to synchronized scans","authors":"Gang Luo, J. Naughton, Curt J. Ellmann, M. Watzke","doi":"10.1145/1458432.1458436","DOIUrl":"https://doi.org/10.1145/1458432.1458436","url":null,"abstract":"Traditional workload management methods mainly focus on the current system status while information about the interaction between queued and running transactions is largely ignored. An exception to this is the transaction reordering method, which reorders the transaction sequence submitted to the RDBMS and improves the transaction throughput by considering both the current system status and information about the interaction between queued and running transactions. The existing transaction reordering method only considers the reordering opportunities provided by analyzing the lock conflict information among multiple transactions. This significantly limits the applicability of the transaction reordering method. In this paper, we extend the existing transaction reordering method into a general transaction reordering framework that can incorporate various factors as the reordering criteria. We show that by analyzing the resource utilization information of transactions, the transaction reordering method can also improve the system throughput by increasing the resource sharing opportunities among multiple transactions. We provide a concrete example on synchronized scans and demonstrate the advantages of our method through experiments with a commercial parallel RDBMS.","PeriodicalId":335396,"journal":{"name":"International Workshop on Data Warehousing and OLAP","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134394456","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}

引用次数: 6

Estimating and bounding aggregations in databases with referential integrity errors 具有参考完整性错误的数据库中聚合的估计和边界

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458442

Javier García-García, C. Ordonez

{"title":"Estimating and bounding aggregations in databases with referential integrity errors","authors":"Javier García-García, C. Ordonez","doi":"10.1145/1458432.1458442","DOIUrl":"https://doi.org/10.1145/1458432.1458442","url":null,"abstract":"Database integration builds on tables coming from multiple databases by creating a single view of all these data. Each database has different tables, columns with similar content across databases and different referential integrity constraints. Thus, a query in an integrated database is likely to involve tables and columns with referential integrity errors. In a data warehouse environment, even though the ETL processes take care of the referential integrity errors, in many scenarios this is generally done by including 'dummy' records in the dimension tables used to relate to the fact tables with referential errors. When two tables are joined, and aggregations are computed, the tuples with an undefined foreign key value are aggregated in a group marked as undefined effectively discarding potentially valuable information. With that motivation in mind, we extend aggregate functions computed over tables with referential integrity errors on OLAP databases to return complete answer sets in the sense that no tuple is excluded. We associate to each valid reference, the probability that an invalid reference may actually be a certain correct reference. The main idea of our work is that in certain contexts, it is possible to use tuples with invalid references by taking into account the probability that an invalid reference actually be a certain correct reference. This way, improved answer sets are obtained from aggregate queries in settings where a database violates referential integrity constraints.","PeriodicalId":335396,"journal":{"name":"International Workshop on Data Warehousing and OLAP","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126348675","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}

引用次数: 3

Semantic enrichment of strategic datacubes 战略数据库的语义丰富

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458447

C. Diamantini, D. Potena

引用次数: 25

Natural language reporting for ETL processes 用于ETL过程的自然语言报告

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458444

A. Simitsis, Dimitrios Skoutas, M. Castellanos

{"title":"Natural language reporting for ETL processes","authors":"A. Simitsis, Dimitrios Skoutas, M. Castellanos","doi":"10.1145/1458432.1458444","DOIUrl":"https://doi.org/10.1145/1458432.1458444","url":null,"abstract":"The conceptual design of the Extract -- Transform -- Load (ETL) processes is a crucial, burdensome, and challenging procedure that takes places at the early phases of a Data Warehouse project. Several models have been proposed for the conceptual design and representation of ETL processes, but all share two inconveniences: they require intensive human effort from the designers to create them, as well as technical knowledge from the business people to understand them. In a previous work, we have relaxed the former difficulty by working on the automation of the conceptual design leveraging Semantic Web technology. In this paper, we built upon our previous results and we tackle the second issue by investigating the application of natural language generation techniques to the ETL environment. In particular, we provide a method for the representation of a conceptual ETL design as a narrative, which is the most natural means of communication and does not require knowledge of any specific model. We discuss how linguistic techniques can be used for the establishment of a common application vocabulary. Finally, we present a flexible and customizable template-based mechanism for generating natural language representations for the ETL process requirements and operations.","PeriodicalId":335396,"journal":{"name":"International Workshop on Data Warehousing and OLAP","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125525396","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}

引用次数: 25

Bridging the semantic gap in OLAP models: platform-independent queries 弥合OLAP模型中的语义差距:与平台无关的查询

International Workshop on Data Warehousing and OLAP Pub Date : 2008-10-30 DOI: 10.1145/1458432.1458448

Jesús Pardillo, J. Mazón, J. Trujillo

{"title":"Bridging the semantic gap in OLAP models: platform-independent queries","authors":"Jesús Pardillo, J. Mazón, J. Trujillo","doi":"10.1145/1458432.1458448","DOIUrl":"https://doi.org/10.1145/1458432.1458448","url":null,"abstract":"The development of data warehouses is based on a three-stage process that starts specifying both the static and dynamic properties of on-line analytical processing (OLAP) applications by means of an intuitive, semantically rich abstraction, namely the conceptual model. Then, developers design its logical counterpart where platform-specific details such as performance or storage are also considered. Nevertheless, it is well known the existence of a semantic gap between the conceptual and logical levels that decreases the feasibility of their mapping. In order to bridge this gap, we propose the use of conceptual OLAP queries, i.e., platform-independent, that can be automatically traced to their logical implementation in a coherent and integrated way. For this aim, in this paper, we focus on describing the specification of an OLAP algebra at the conceptual level by using the object-constraint language (OCL). Its operations are then translated into a particular OLAP system by using a model-driven architecture (MDA). The great advantage of our approach is that we allow analysts to query data warehouses without being aware of logical details.","PeriodicalId":335396,"journal":{"name":"International Workshop on Data Warehousing and OLAP","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114204289","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}

引用次数: 24

Deciding the physical implementation of ETL workflows 决定ETL工作流的物理实现

International Workshop on Data Warehousing and OLAP Pub Date : 2007-11-09 DOI: 10.1145/1317331.1317341

Vasiliki Tziovara, Panos Vassiliadis, A. Simitsis

引用次数: 90

Improving business intelligence speed and quality through the OODA concept 通过OODA概念提高商业智能的速度和质量

International Workshop on Data Warehousing and OLAP Pub Date : 2007-11-09 DOI: 10.1145/1317331.1317349

Morten Middelfart

引用次数: 16

Mining unexpected multidimensional rules 挖掘意外的多维规则

International Workshop on Data Warehousing and OLAP Pub Date : 2007-11-09 DOI: 10.1145/1317331.1317347

M. Plantevit, S. Goutier, F. Guisnel, Anne Laurent, M. Teisseire

引用次数: 10