Statistical information extraction (IE) programs are increasingly used to build real-world IE systems such as Alibaba, CiteSeer, Kylin, and YAGO. Current statistical IE approaches consider the text corpora underlying the extraction program to be static. However, many real-world text corpora are dynamic (documents are inserted, modified, and removed). As the corpus evolves, and IE programs must be applied repeatedly to consecutive corpus snapshots to keep extracted information up to date. Applying IE from scratch to each snapshot may be inefficient: a pair of consecutive snapshots may change very little, but unaware of this, the program must run again from scratch. In this paper, we present CRFlex, a system that efficiently executes such repeated statistical IE, by recycling previous IE results to enable incremental update. As the first step, CRFlex focuses on statistical IE programs which use a leading statistical model, Conditional Random Fields (CRFs). We show how to model properties of the CRF inference algorithms for incremental update and how to exploit them to correctly recycle previous inference results. Then we show how to efficiently capture and store intermediate results of IE programs for subsequent recycling. We find that there is a tradeoff between the I/O cost spent on reading and writing intermediate results, and CPU cost we can save from recycling those intermediate results. Therefore we present a cost-based solution to determine the most efficient recycling approach for any given CRF-based IE program and an evolving corpus. We conduct extensive experiments with CRF-based IE programs for 3 IE tasks over a real-world data set to demonstrate the utility of our approach.
{"title":"Optimizing Statistical Information Extraction Programs over Evolving Text","authors":"Fei Chen, Xixuan Feng, C. Ré, Min Wang","doi":"10.1109/ICDE.2012.60","DOIUrl":"https://doi.org/10.1109/ICDE.2012.60","url":null,"abstract":"Statistical information extraction (IE) programs are increasingly used to build real-world IE systems such as Alibaba, CiteSeer, Kylin, and YAGO. Current statistical IE approaches consider the text corpora underlying the extraction program to be static. However, many real-world text corpora are dynamic (documents are inserted, modified, and removed). As the corpus evolves, and IE programs must be applied repeatedly to consecutive corpus snapshots to keep extracted information up to date. Applying IE from scratch to each snapshot may be inefficient: a pair of consecutive snapshots may change very little, but unaware of this, the program must run again from scratch. In this paper, we present CRFlex, a system that efficiently executes such repeated statistical IE, by recycling previous IE results to enable incremental update. As the first step, CRFlex focuses on statistical IE programs which use a leading statistical model, Conditional Random Fields (CRFs). We show how to model properties of the CRF inference algorithms for incremental update and how to exploit them to correctly recycle previous inference results. Then we show how to efficiently capture and store intermediate results of IE programs for subsequent recycling. We find that there is a tradeoff between the I/O cost spent on reading and writing intermediate results, and CPU cost we can save from recycling those intermediate results. Therefore we present a cost-based solution to determine the most efficient recycling approach for any given CRF-based IE program and an evolving corpus. We conduct extensive experiments with CRF-based IE programs for 3 IE tasks over a real-world data set to demonstrate the utility of our approach.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"357 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115469920","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}
C. Doulkeridis, Akrivi Vlachou, K. Nørvåg, Y. Kotidis, N. Polyzotis
In this paper, we study efficient processing of rank joins in highly distributed systems, where servers store fragments of relations in an autonomous manner. Existing rank-join algorithms exhibit poor performance in this setting due to excessive communication costs or high latency. We propose a novel distributed rank-join framework that employs data statistics, maintained as histograms, to determine the subset of each relational fragment that needs to be fetched to generate the top-k join results. At the heart of our framework lies a distributed score bound estimation algorithm that produces sufficient score bounds for each relation, that guarantee the correctness of the rank-join result set, when the histograms are accurate. Furthermore, we propose a generalization of our framework that supports approximate statistics, in the case that the exact statistical information is not available. An extensive experimental study validates the efficiency of our framework and demonstrates its advantages over existing methods.
{"title":"Processing of Rank Joins in Highly Distributed Systems","authors":"C. Doulkeridis, Akrivi Vlachou, K. Nørvåg, Y. Kotidis, N. Polyzotis","doi":"10.1109/ICDE.2012.108","DOIUrl":"https://doi.org/10.1109/ICDE.2012.108","url":null,"abstract":"In this paper, we study efficient processing of rank joins in highly distributed systems, where servers store fragments of relations in an autonomous manner. Existing rank-join algorithms exhibit poor performance in this setting due to excessive communication costs or high latency. We propose a novel distributed rank-join framework that employs data statistics, maintained as histograms, to determine the subset of each relational fragment that needs to be fetched to generate the top-k join results. At the heart of our framework lies a distributed score bound estimation algorithm that produces sufficient score bounds for each relation, that guarantee the correctness of the rank-join result set, when the histograms are accurate. Furthermore, we propose a generalization of our framework that supports approximate statistics, in the case that the exact statistical information is not available. An extensive experimental study validates the efficiency of our framework and demonstrates its advantages over existing methods.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126019518","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}
This paper addresses the challenges faced by everyday Web users, who interact with inherently heterogeneous and distributed information. Managing such data is currently beyond the skills of casual users. We describe ongoing work that has as its goal the development of foundations for declarative distributed data management. In this approach, we see the Web as a knowledge base consisting of distributed logical facts and rules. Our objective is to enable automated reasoning over this knowledge base, ultimately improving the quality of service and of data. For this, we use Webdamlog, a Datalog-style language with rule delegation. We outline ongoing efforts on the Web dam Exchange platform that combines Webdamlog evaluation with communication and security protocols.
{"title":"Viewing the Web as a Distributed Knowledge Base","authors":"S. Abiteboul, Émilien Antoine, Julia Stoyanovich","doi":"10.1109/ICDE.2012.150","DOIUrl":"https://doi.org/10.1109/ICDE.2012.150","url":null,"abstract":"This paper addresses the challenges faced by everyday Web users, who interact with inherently heterogeneous and distributed information. Managing such data is currently beyond the skills of casual users. We describe ongoing work that has as its goal the development of foundations for declarative distributed data management. In this approach, we see the Web as a knowledge base consisting of distributed logical facts and rules. Our objective is to enable automated reasoning over this knowledge base, ultimately improving the quality of service and of data. For this, we use Webdamlog, a Datalog-style language with rule delegation. We outline ongoing efforts on the Web dam Exchange platform that combines Webdamlog evaluation with communication and security protocols.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"64 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126087540","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}
The abundance of Web 2.0 resources in various media formats calls for better resource integration to enrich user experience. This naturally leads to a new cross-modal resource search requirement, in which a query is a resource in one modal and the results are closely related resources in other modalities. With cross-modal search, we can better exploit existing resources. Tags associated with Web 2.0 resources are intuitive medium to link resources with different modality together. However, tagging is by nature an ad hoc activity. They often contain noises and are affected by the subjective inclination of the tagger. Consequently, linking resources simply by tags will not be reliable. In this paper, we propose an approach for linking tagged resources to concepts extracted from Wikipedia, which has become a fairly reliable reference over the last few years. Compared to the tags, the concepts are therefore of higher quality. We develop effective methods for cross-modal search based on the concepts associated with resources. Extensive experiments were conducted, and the results show that our solution achieves good performance.
{"title":"Cross Domain Search by Exploiting Wikipedia","authors":"Chen Liu, Sai Wu, Shouxu Jiang, A. Tung","doi":"10.1109/ICDE.2012.13","DOIUrl":"https://doi.org/10.1109/ICDE.2012.13","url":null,"abstract":"The abundance of Web 2.0 resources in various media formats calls for better resource integration to enrich user experience. This naturally leads to a new cross-modal resource search requirement, in which a query is a resource in one modal and the results are closely related resources in other modalities. With cross-modal search, we can better exploit existing resources. Tags associated with Web 2.0 resources are intuitive medium to link resources with different modality together. However, tagging is by nature an ad hoc activity. They often contain noises and are affected by the subjective inclination of the tagger. Consequently, linking resources simply by tags will not be reliable. In this paper, we propose an approach for linking tagged resources to concepts extracted from Wikipedia, which has become a fairly reliable reference over the last few years. Compared to the tags, the concepts are therefore of higher quality. We develop effective methods for cross-modal search based on the concepts associated with resources. Extensive experiments were conducted, and the results show that our solution achieves good performance.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"4 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116627303","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}
Previous work has introduced probability distributions as first-class components in uncertain stream database systems. A lacking element is the fact of how accurate these probability distributions are. This indeed has a profound impact on the accuracy of query results presented to end users. While there is some previous work that studies unreliable intermediate query results in the tuple uncertainty model, to the best of our knowledge, we are the first to consider an uncertain stream database in which accuracy is taken into consideration all the way from the learned distributions based on raw data samples to the query results. We perform an initial study of various components in an accuracy-aware uncertain stream database system, including the representation of accuracy information and how to obtain query results' accuracy. In addition, we propose novel predicates based on hypothesis testing for decision-making using data with limited accuracy. We augment our study with a comprehensive set of experimental evaluations.
{"title":"Accuracy-Aware Uncertain Stream Databases","authors":"Tingjian Ge, Fujun Liu","doi":"10.1109/ICDE.2012.96","DOIUrl":"https://doi.org/10.1109/ICDE.2012.96","url":null,"abstract":"Previous work has introduced probability distributions as first-class components in uncertain stream database systems. A lacking element is the fact of how accurate these probability distributions are. This indeed has a profound impact on the accuracy of query results presented to end users. While there is some previous work that studies unreliable intermediate query results in the tuple uncertainty model, to the best of our knowledge, we are the first to consider an uncertain stream database in which accuracy is taken into consideration all the way from the learned distributions based on raw data samples to the query results. We perform an initial study of various components in an accuracy-aware uncertain stream database system, including the representation of accuracy information and how to obtain query results' accuracy. In addition, we propose novel predicates based on hypothesis testing for decision-making using data with limited accuracy. We augment our study with a comprehensive set of experimental evaluations.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114073853","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}
Tobias Emrich, H. Kriegel, N. Mamoulis, M. Renz, Andreas Züfle
The problem of modeling and managing uncertain data has received a great deal of interest, due to its manifold applications in spatial, temporal, multimedia and sensor databases. There exists a wide range of work covering spatial uncertainty in the static (snapshot) case, where only one point of time is considered. In contrast, the problem of modeling and querying uncertain spatio-temporal data has only been treated as a simple extension of the spatial case, disregarding time dependencies between consecutive timestamps. In this work, we present a framework for efficiently modeling and querying uncertain spatio-temporal data. The key idea of our approach is to model possible object trajectories by stochastic processes. This approach has three major advantages over previous work. First it allows answering queries in accordance with the possible worlds model. Second, dependencies between object locations at consecutive points in time are taken into account. And third it is possible to reduce all queries on this model to simple matrix multiplications. Based on these concepts we propose efficient solutions for different probabilistic spatio-temporal queries. In an experimental evaluation we show that our approaches are several order of magnitudes faster than state-of-the-art competitors.
{"title":"Querying Uncertain Spatio-Temporal Data","authors":"Tobias Emrich, H. Kriegel, N. Mamoulis, M. Renz, Andreas Züfle","doi":"10.1109/ICDE.2012.94","DOIUrl":"https://doi.org/10.1109/ICDE.2012.94","url":null,"abstract":"The problem of modeling and managing uncertain data has received a great deal of interest, due to its manifold applications in spatial, temporal, multimedia and sensor databases. There exists a wide range of work covering spatial uncertainty in the static (snapshot) case, where only one point of time is considered. In contrast, the problem of modeling and querying uncertain spatio-temporal data has only been treated as a simple extension of the spatial case, disregarding time dependencies between consecutive timestamps. In this work, we present a framework for efficiently modeling and querying uncertain spatio-temporal data. The key idea of our approach is to model possible object trajectories by stochastic processes. This approach has three major advantages over previous work. First it allows answering queries in accordance with the possible worlds model. Second, dependencies between object locations at consecutive points in time are taken into account. And third it is possible to reduce all queries on this model to simple matrix multiplications. Based on these concepts we propose efficient solutions for different probabilistic spatio-temporal queries. In an experimental evaluation we show that our approaches are several order of magnitudes faster than state-of-the-art competitors.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133992827","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}
Estimating the global data distribution in Peer-to-Peer (P2P) networks is an important issue and has yet to be well addressed. It can benefit many P2P applications, such as load balancing analysis, query processing, and data mining. Inspired by the inversion method for random variate generation, in this paper we present a novel model named distribution-free data density estimation for dynamic ring-based P2P networks to achieve high estimation accuracy with low estimation cost regardless of distribution models of the underlying data. It generates random samples for any arbitrary distribution by sampling the global cumulative distribution function and is free from sampling bias. In P2P networks, the key idea for distribution-free estimation is to sample a small subset of peers for estimating the global data distribution over the data domain. Algorithms on computing and sampling the global cumulative distribution function based on which global data distribution is estimated are introduced with detailed theoretical analysis. Our extensive performance study confirms the effectiveness and efficiency of our methods in ring-based P2P networks.
{"title":"Effective Data Density Estimation in Ring-Based P2P Networks","authors":"Minqi Zhou, Heng Tao Shen, Xiaofang Zhou, Weining Qian, Aoying Zhou","doi":"10.1109/ICDE.2012.19","DOIUrl":"https://doi.org/10.1109/ICDE.2012.19","url":null,"abstract":"Estimating the global data distribution in Peer-to-Peer (P2P) networks is an important issue and has yet to be well addressed. It can benefit many P2P applications, such as load balancing analysis, query processing, and data mining. Inspired by the inversion method for random variate generation, in this paper we present a novel model named distribution-free data density estimation for dynamic ring-based P2P networks to achieve high estimation accuracy with low estimation cost regardless of distribution models of the underlying data. It generates random samples for any arbitrary distribution by sampling the global cumulative distribution function and is free from sampling bias. In P2P networks, the key idea for distribution-free estimation is to sample a small subset of peers for estimating the global data distribution over the data domain. Algorithms on computing and sampling the global cumulative distribution function based on which global data distribution is estimated are introduced with detailed theoretical analysis. Our extensive performance study confirms the effectiveness and efficiency of our methods in ring-based P2P networks.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"8 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130356811","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}
Zhitao Shen, M. A. Cheema, Xuemin Lin, W. Zhang, Haixun Wang
Top-k pairs queries have received significant attention by the research community. k-closest pairs queries, k-furthest pairs queries and their variants are among the most well studied special cases of the top-k pairs queries. In this paper, we present the first approach to answer a broad class of top-k pairs queries over sliding windows. Our framework handles multiple top-k pairs queries and each query is allowed to use a different scoring function, a different value of k and a different size of the sliding window. Although the number of possible pairs in the sliding window is quadratic to the number of objects N in the sliding window, we efficiently answer the top-k pairs query by maintaining a small subset of pairs called K-sky band which is expected to consist of O(K log(N/K)) pairs. For all the queries that use the same scoring function, we need to maintain only one K-sky band. We present efficient techniques for the K-sky band maintenance and query answering. We conduct a detailed complexity analysis and show that the expected cost of our approach is reasonably close to the lower bound cost. We experimentally verify this by comparing our approach with a specially designed supreme algorithm that assumes the existence of an oracle and meets the lower bound cost.
{"title":"Efficiently Monitoring Top-k Pairs over Sliding Windows","authors":"Zhitao Shen, M. A. Cheema, Xuemin Lin, W. Zhang, Haixun Wang","doi":"10.1109/ICDE.2012.89","DOIUrl":"https://doi.org/10.1109/ICDE.2012.89","url":null,"abstract":"Top-k pairs queries have received significant attention by the research community. k-closest pairs queries, k-furthest pairs queries and their variants are among the most well studied special cases of the top-k pairs queries. In this paper, we present the first approach to answer a broad class of top-k pairs queries over sliding windows. Our framework handles multiple top-k pairs queries and each query is allowed to use a different scoring function, a different value of k and a different size of the sliding window. Although the number of possible pairs in the sliding window is quadratic to the number of objects N in the sliding window, we efficiently answer the top-k pairs query by maintaining a small subset of pairs called K-sky band which is expected to consist of O(K log(N/K)) pairs. For all the queries that use the same scoring function, we need to maintain only one K-sky band. We present efficient techniques for the K-sky band maintenance and query answering. We conduct a detailed complexity analysis and show that the expected cost of our approach is reasonably close to the lower bound cost. We experimentally verify this by comparing our approach with a specially designed supreme algorithm that assumes the existence of an oracle and meets the lower bound cost.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132875048","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}
Sub graph search is a popular query scenario on graph databases. Given a query graph q, the sub graph search algorithm returns all database graphs having q as a sub graph. To efficiently implement a subgraph search, subgraph features are mined in order to index the graph database. Many subgraph feature mining approaches have been proposed. They are all "mine-at-once" algorithms in which the whole feature set is mined in one run before building a stable graph index. However, due to the change of environments (such as an update of the graph database and the increase of available memory), the index needs to be updated to accommodate such changes. Most of the "mine-at-once" algorithms involve frequent subgraph or subtree mining over the whole graph database. Also, constructing and deploying a new index involves an expensive disk operation such that it is inefficient to re-mine the features and rebuild the index from scratch. We observe that, under most cases, it is sufficient to update a small part of the graph index. Here we propose an "iterative subgraph mining" algorithm which iteratively finds one feature to insert into (or remove from) the index. Since the majority of indexing features and the index structure are not changed, the algorithm can be frequently invoked. We define an objective function that guides the feature mining. Next, we propose a basic branch and bound algorithm to mine the features. Finally, we design an advanced search algorithm, which quickly finds a near-optimum subgraph feature and reduces the search space. Experiments show that our feature mining algorithm is 5 times faster than the popular graph indexing algorithm gIndex, and that features mined by our iterative algorithm have a better filtering rate for the subgraph search problem.
{"title":"Iterative Graph Feature Mining for Graph Indexing","authors":"Dayu Yuan, P. Mitra, Huiwen Yu, C. Lee Giles","doi":"10.1109/ICDE.2012.11","DOIUrl":"https://doi.org/10.1109/ICDE.2012.11","url":null,"abstract":"Sub graph search is a popular query scenario on graph databases. Given a query graph q, the sub graph search algorithm returns all database graphs having q as a sub graph. To efficiently implement a subgraph search, subgraph features are mined in order to index the graph database. Many subgraph feature mining approaches have been proposed. They are all \"mine-at-once\" algorithms in which the whole feature set is mined in one run before building a stable graph index. However, due to the change of environments (such as an update of the graph database and the increase of available memory), the index needs to be updated to accommodate such changes. Most of the \"mine-at-once\" algorithms involve frequent subgraph or subtree mining over the whole graph database. Also, constructing and deploying a new index involves an expensive disk operation such that it is inefficient to re-mine the features and rebuild the index from scratch. We observe that, under most cases, it is sufficient to update a small part of the graph index. Here we propose an \"iterative subgraph mining\" algorithm which iteratively finds one feature to insert into (or remove from) the index. Since the majority of indexing features and the index structure are not changed, the algorithm can be frequently invoked. We define an objective function that guides the feature mining. Next, we propose a basic branch and bound algorithm to mine the features. Finally, we design an advanced search algorithm, which quickly finds a near-optimum subgraph feature and reduces the search space. Experiments show that our feature mining algorithm is 5 times faster than the popular graph indexing algorithm gIndex, and that features mined by our iterative algorithm have a better filtering rate for the subgraph search problem.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"245 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132291337","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}
Michael Busch, Krishna Gade, B. Larson, Patrick Lok, Samuel B. Luckenbill, Jimmy J. Lin
The web today is increasingly characterized by social and real-time signals, which we believe represent two frontiers in information retrieval. In this paper, we present Early bird, the core retrieval engine that powers Twitter's real-time search service. Although Early bird builds and maintains inverted indexes like nearly all modern retrieval engines, its index structures differ from those built to support traditional web search. We describe these differences and present the rationale behind our design. A key requirement of real-time search is the ability to ingest content rapidly and make it searchable immediately, while concurrently supporting low-latency, high-throughput query evaluation. These demands are met with a single-writer, multiple-reader concurrency model and the targeted use of memory barriers. Early bird represents a point in the design space of real-time search engines that has worked well for Twitter's needs. By sharing our experiences, we hope to spur additional interest and innovation in this exciting space.
{"title":"Earlybird: Real-Time Search at Twitter","authors":"Michael Busch, Krishna Gade, B. Larson, Patrick Lok, Samuel B. Luckenbill, Jimmy J. Lin","doi":"10.1109/ICDE.2012.149","DOIUrl":"https://doi.org/10.1109/ICDE.2012.149","url":null,"abstract":"The web today is increasingly characterized by social and real-time signals, which we believe represent two frontiers in information retrieval. In this paper, we present Early bird, the core retrieval engine that powers Twitter's real-time search service. Although Early bird builds and maintains inverted indexes like nearly all modern retrieval engines, its index structures differ from those built to support traditional web search. We describe these differences and present the rationale behind our design. A key requirement of real-time search is the ability to ingest content rapidly and make it searchable immediately, while concurrently supporting low-latency, high-throughput query evaluation. These demands are met with a single-writer, multiple-reader concurrency model and the targeted use of memory barriers. Early bird represents a point in the design space of real-time search engines that has worked well for Twitter's needs. By sharing our experiences, we hope to spur additional interest and innovation in this exciting space.","PeriodicalId":321608,"journal":{"name":"2012 IEEE 28th International Conference on Data Engineering","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132296812","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}