Fast small-space algorithms for approximate histogram maintenance (2009)
Anna C. Gilbert, Yannis Kotidis
Avector A of lengthN is de ned implicitly, via a stream of updates of the form \add 5 to A3. " We give asketching algorithm, that constructs a small sketch from the stream of updates, and a...
ABSTRACT Peer-to-Peer Similarity Search in Metric Spaces (2008)
Christos Doulkeridis, Akrivi Vlachou, Yannis Kotidis, Michalis Vazirgiannis
This paper addresses the efficient processing of similarity queries in metric spaces, where data is horizontally distributed across a P2P network. The proposed approach does not rely on arbitrary...
Fast small-space algorithms for approximate histogram maintenance (2008)
Anna C. Gilbert, Yannis Kotidis
Avector A of lengthN is de ned implicitly, via a stream of updates of the form \add 5 to A3. " We give asketching algorithm, that constructs a small sketch from the stream of updates, and a...
ABSTRACT Robust Management of Outliers in Sensor Network Aggregate Queries ∗ (2008)
Yannis Kotidis, Vasilis Vassalos
Sensor networks are increasingly applied for monitoring diverse environments and applications. Due to their unsupervised nature of operation and inexpensive hardware used, sensor nodes may furnish...
Abstract DynaMat: A Dynamic View Management System for Data Warehouses (2008)
Pre-computation and materialization of views with aggregate functions is a common technique in Data Warehouses. Due to the complex structure of the warehouse and the different profiles of the users...
Flip Korn, Ros Labrinidis, Yannis Kotidis, Christos Faloutsos
a data matrix (e.g., customers products) to derive association rules (Agrawal, Imielinski, & Swami, 1993b; Srikant & Agrawal, 1996). We propose a new paradigm, namely, Ratio Rules, which are...
Extending the Data Warehouse for Service Provisioning Data (2008)
The last few years, there has been an extensive body of literature in data warehousing applications that primarily focuses on basket-type (transactional) data, common in retail industries. In this...
The Opsis Project: Materialized Views for Data Warehouses and the Web (2008)
Nick Roussopoulos, Yannis Kotidis, Ros Labrinidis, Yannis Sismanis
Abstract. The real world we live in is mostly perceived through an incredibly large collection of views generated by humans, machines, and other systems. This is the view reality. The Opsis project...
ABSTRACT Robust Management of Outliers in Sensor Network Aggregate Queries (2008)
Yannis Kotidis, Vasilis Vassalos
Sensor networks are increasingly applied for monitoring diverse environments and applications. Due to their unsupervised nature of operation and inexpensive hardware used, sensor nodes may furnish...
Bandwidth-Constrained Queries in Sensor Networks (2008)
Antonios Deligiannakis, Yannis Kotidis, Nick Roussopoulos, A. Deligiannakis, N. Roussopoulos
Sensor networks consist of battery-powered wireless devices that are required to operate unattended for long periods of time. Thus, reducing energy drain is of utmost importance when designing...
The Opsis Project: Materialized Views for Data Warehouses and the Web (2008)
Nick Roussopoulos, Yannis Kotidis, Alexandros Labrinidis, Ros Labrinidis, Yannis Sismanis
The real world we live in is mostly perceived through an incredibly large collection of views generated by humans, machines, and other systems. This is the view reality.
Quantifiable Data Mining Using Ratio Rules (2007)
Flip Korn, Alexandros Labrinidis, Yannis Kotidis, Christos Faloutsos
Association Rule Mining algorithms operate on a data matrix (e.g., customers \Theta products) to derive association rules (Agrawal, Imielinski, & Swami, 1993b; Srikant & Agrawal, 1996). We...
Yannis Kotidis, Yannis Sismanis, Nick Roussopoulos
Abstract. In this paper we propose a new \transcurrent execution model" (TEM) for concurrent user queries against tree indexes. Our model exploits intra-parallelism of the index scan and...
A Data Warehousing Architecture for Enabling Service Provisioning Process (2007)
In this paper we focus on the following problem in information management: given a large collection of recorded information and some knowledge of the process that is generating this data we want to...
Anna C. Gilbert, Sudipto Guha, Piotr Indyk, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
A vector A of length N is defined implicitly, via a stream of updates of the form "add 5 to A 3. " We give a sketching algorithm, that constructs a small sketch from the stream of...
The VLDB Journal manuscript No. (2007)
Will Be Inserted, Alexandros Labrinidis, Yannis Kotidis, Christos Faloutsos
Association Rule Mining algorithms operate on a data matrix (e.g., customers \Theta products) to derive association rules (Agrawal, Imielinski, & Swami, 1993b; Srikant & Agrawal, 1996). We...
SKYPEER: Efficient subspace skyline computation over distributed data (2007)
Akrivi Vlachou, Christos Doulkeridis, Yannis Kotidis
Skyline query processing has received considerable attention in the recent past. Mainly, the skyline query is used to find a set of non dominated data points in a multidimensional dataset. While most...
Peer-to-peer similarity search in metric spaces (2007)
Christos Doulkeridis, Akrivi Vlachou, Yannis Kotidis, Michalis Vazirgiannis
This paper addresses the efficient processing of similarity queries in metric spaces, where data is horizontally distributed across a P2P network. The proposed approach does not rely on arbitrary...
Processing Proximity Queries in Sensor Networks (2006)
Sensor networks are often used to perform monitoring tasks, such as in animal or vehicle tracking and in surveillance of enemy forces in military applications. In this paper we introduce the concept...
Circumventing Data Quality Problems (2006)
Using Multiple Join, Yannis Kotidis, Amélie Marian
We propose the Multiple Join Path (MJP) framework for obtaining high quality information by linking fields across multiple databases, when the underlying databases have poor quality data, which are...
Data Reduction Techniques in Sensor Networks (2005)
Antonios Deligiannakis, Yannis Kotidis
Recent advances in microelectronics have made feasible the deployment of sensor networks for a variety of monitoring and surveillance tasks. The severe energy constraints met in such networks make...
Processing Approximate Aggregate Queries in Wireless Sensor Networks (2005)
Antonios Deligiannakis, Yannis Kotidis, Nick Roussopoulos
In-network data aggregation has been recently proposed as an e#ective means to reduce the number of messages exchanged in wireless sensor networks. Nodes of the network form an aggregation tree, in...
Snapshot Queries: Towards Data-Centric Sensor Networks (2005)
In this paper we introduce the idea of snapshot queries for energy efficient data acquisition in sensor networks. Network nodes generate models of their surrounding environment that are used for...
Domain-driven data synopses for dynamic quantiles (2005)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Abstract—In this paper, we present new algorithms for dynamically computing quantiles of a relation subject to insert as well as delete operations. At the core of our algorithms lies a small-space...
Web-services architecture for efficient XML data exchange (2004)
Sihem Amer-yahia, Yannis Kotidis
Business applications often exchange large amounts of enterprise data stored in legacy systems. The advent of XML as a standard specification format has improved applications interoperability....
Hierarchical In-Network Data Aggregation with Quality Guarantees (2004)
Antonios Deligiannakis, Yannis Kotidis, Nick Roussopoulos
Earlier work has demonstrated the effectiveness of in-network data aggregation in order to minimize the amount of messages exchanged during continuous queries in large sensor networks. The key idea...
Teaching Relational Optimizers about XML Processing (2004)
Sihem Amer-yahia, Yannis Kotidis, Divesh Srivastava
Due to their numerous benefits, relational systems play a major role in storing XML documents. XML also benefits relational systems by providing a means to publish legacy relational data....
Teaching Relational Optimizers about XML Processing (2004)
Sihem Amer-yahia, Yannis Kotidis, Divesh Srivastava
Due to their numerous benefits, relational systems play a major role in storing XML documents. XML also benefits relational systems by providing a means to publish legacy relational data....
Data Reduction Techniques for Sensor Networks (2003)
Deligiannakis, Antonios, Kotidis, Yannis, Roussopoulos, Nick
We are inevitably moving into a realm where small and inexpensive wireless devices would be seamlessly embedded in the physical world and form a wireless sensor network in order to perform complex...
Data Reduction Techniques for Sensor Networks (2003)
Deligiannakis, Antonios, Kotidis, Yannis, Roussopoulos, Nick
We are inevitably moving into a realm where small and inexpensive wireless devices would be seamlessly embedded in the physical world and form a wireless sensor network in order to perform complex...
Panayiotis Tsaparas, Themistoklis Palpanas, Yannis Kotidis, Nick Koudas, Divesh Srivastava
A plethora of data sources contain data entities that could be ordered according to a variety of attributes associated with the entities. Such orderings result effectively in a ranking of the...
One-Pass Wavelet Decompositions of Data Streams (2003)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
Hierarchical Dwarfs for the Rollup Cube (2003)
Yannis Sismanis, Antonios Deligiannakis, Yannis Kotidis, Nick Roussopoulos
The data cube operator exemplifies two of the most important aspects of OLAP queries: aggregation and dimension hierarchies. In earlier work we presented Dwarf, a highly compressed and clustered...
Dwarf: Shrinking the PetaCube (2002)
Sismanis, Yannis, Deligiannakis, Antonios, Roussopoulos, Nick, Kotidis, Yannis
Dwarf is a highly compressed structure for computing, storing, and querying data cubes. Dwarf identifies prefix and suffix structural redundancies and factors them out by coalescing their store....
Dwarf: Shrinking the PetaCube (2002)
Sismanis, Yannis, Deligiannakis, Antonios, Roussopoulos, Nick, Kotidis, Yannis
Dwarf is a highly compressed structure for computing, storing, and querying data cubes. Dwarf identifies prefix and suffix structural redundancies and factors them out by coalescing their store....
Dwarf: Shrinking the petacube (2002)
Yannis Sismanis, Antonios Deligiannakis, Nick Roussopoulos, Yannis Kotidis
Dwarf is a highly compressed structure for computing, storing, and querying data cubes. Dwarf identifies prefix and suffix structural redundancies and factors them out by coalescing their store....
How to summarize the universe: Dynamic maintenance of quantiles (2002)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Order statistics, i.e., quantiles, are frequently used in databases both at the database server as well as the application level. For example, they are useful in selectivity estimation during query...
Dwarf: Shrinking the PetaCube (2002)
Yannis Sismanis, Antonios Deligiannakis, Nick Roussopoulos, Yannis Kotidis
Dwarf is a highly compressed structure for computing, storing, and querying data cubes. Dwarf identifies prefix and suffix structural redundancies and factors them out by coalescing their store....
Fast, Small-Space Algorithms for Approximate Histogram Maintenance (Extended Abstract) (2002)
Anna Gilbert, Yannis Kotidis, Sudipto Guha, S. Muthukrishnan, Piotr Indyk, Martin J. Strauss
Anna C. Gilbert AT&T Labs---Research agilbert@research.att.com Yannis Kotidis AT&T Labs---Research kotidis@research.att.com Sudipto Guha CIS,University of Pennsylvania sudipto@cis.upenn.edu...
Fast, Small-Space Algorithms for Approximate Histogram (2002)
Maintenance Extend Ed, Anna C. Gilbert, Sudipto Guha, Piotr Indyk, Yannis Kotidis, S. Muthukrishnan, ...
Anna C. Gilbert AT&T Labs---Research agilbert@research.att.com Yannis Kotidis AT&T Labs---Research kotidis@research.att.com Sudipto Guha CIS,University of Pennsylvania sudipto@cis.upenn.edu...
How to Summarize the Universe: Dynamic Maintenance of Quantiles (2002)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Order statistics, i.e., quantiles, are frequently used in databases both at the database server as well as the application level. For example, they are useful in selectivity estimation during query...
How to summarize the universe: Dynamic maintenance of quantiles (2002)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Abstract Order statistics, i.e., quantiles, are frequently used in databases both at the database server as well as the application level. For example, they are useful in selectivity estimation...
Shared Index Scans For Data Warehouses (2001)
Kotidis, Yannis, Sismanis, Yannis, Roussopoulos, Nick
Tree based indexing structures like B-trees, B+trees, Bitmap indexes and R-trees have become essential for getting good performance when accessing vast datasets. However, most database research seems...
Shared Index Scans For Data Warehouses (2001)
Kotidis, Yannis, Sismanis, Yannis, Roussopoulos, Nick
Tree based indexing structures like B-trees, B+trees, Bitmap indexes and R-trees have become essential for getting good performance when accessing vast datasets. However, most database research seems...
Optimal and approximate computation of summary statistics for range aggregates (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Fast estimates for aggregate queries are useful in database query optimization, approximate query answering and online query processing. Hence, there has been a lot of focus on “selectivity...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Abstract We present techniques for computing small spacerepresentations of massive data streams. These are inspired by traditional wavelet-based approx-imations that consist of specific linear...
A case for dynamic view management (2001)
Yannis Kotidis, Nick Roussopoulos
Materialized aggregate views represent a set of redundant entities in a data warehouse that are frequently used to accelerate On-Line Analytical Processing (OLAP). Due to the complex structure of the...
Optimal and approximate computation of summary statistics for range aggregates (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
Fast estimates for aggregate queries are useful in database query optimization, approximate query answering and online query processing. Hence, there has been a lot of focus on "selectivity...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
Shared index scans for data warehouses (2001)
Yannis Kotidis, Yannis Sismanis, Nick Roussopoulos
Abstract. Tree based indexing structures like B-trees, B-trees, Bitmap indexes and R-trees have become essential for getting good performance when accessing vast datasets. However, most database...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
Surfing wavelets on streams: One-pass summaries for approximate aggregate queries (2001)
Anna C. Gilbert, Yannis Kotidis, S. Muthukrishnan, Martin J. Strauss
We present techniques for computing small space representations of massive data streams. These are inspired by traditional wavelet-based approximations that consist of specific linear projections of...
View management in data warehouses /--by Ioannis Kotidis. (2000)
Thesis research directed by Dept. of Computer Science.
DynaMat: A Dynamic View Management System for Data Warehouses (1999)
Yannis Kotidis, Nick Roussopoulos
Pre-computation and materialization of views with aggregate functions is a common technique in Data Warehouses. Due to the complex structure of the warehouse and the different profiles of the users...
DynaMat: A Dynamic View Management System for Data Warehouses (1999)
Yannis Kotidis, Nick Roussopoulos
Pre-computation and materialization of views with aggregate functions is a common technique in Data Warehouses. Due to the complex structure of the warehouse and the different profiles of the users...
An Alternative Storage Organization for ROLAP Aggregate Views Based on Cubetrees (1998)
Yannis Kotidis, Nick Roussopoulos
The Relational On-Line Analytical Processing (ROLAP) is emerging as the dominant approach in data warehousing with decision support applications. In order to enhance query performance, the ROLAP...
Ratio Rules: A New Paradigm for Fast, Quantifiable Data Mining (1998)
Flip Korn, Alexandros Labrinidis, Ros Labrinidis, Yannis Kotidis, Christos Faloutsos
Association Rule Mining algorithms operate on a data matrix (e.g., customers \Theta products) to derive association rules [2, 23]. We propose a new paradigm, namely, Ratio Rules, which are...
An alternative storage organization for ROLAP aggregate views based on cubetrees (1998)
as the dominant approach in data warehousing with decision support applications. In order to enhance query performance, the RO-LAP approach relies on selecting and materializing in summary tables...
An alternative storage organization for ROLAP aggregate views based on cubetrees (1998)
as the dominant approach in data warehousing with decision support applications. In order to enhance query performance, the RO-LAP approach relies on selecting and materializing in summary tables...
A Generalized Framework for Indexing OLAP Aggregates (1997)
Decision support applications often require fast response time to a wide variety of aggregate queries extracted from huge amounts of data. In this paper we propose the use of well organized packed...
A Generalized Framework for Indexing OLAP Aggregates (1997)
Decision support applications often require fast response time to a wide variety of aggregate queries extracted from huge amounts of data. In this paper we propose the use of well organized packed...
Quantifiable Data Mining Using Principal Component Analysis (1997)
Korn, Flip, Labrinidis, Alexandros, Kotidis, Yannis, Faloutsos, Christos, Kaplunovich, Alex, Perkovic, Dejan
Association Rule Mining algorithms operate on a data matrix (e.g., customers x products) to derive rules. We propose a single-pass algorithm for mining linear rules in such a matrix based on...
Quantifiable Data Mining Using Principal Component Analysis (1997)
Korn, Flip, Labrinidis, Alexandros, Kotidis, Yannis, Faloutsos, Christos, Kaplunovich, Alex, Perkovic, Dejan
Association Rule Mining algorithms operate on a data matrix (e.g., customers x products) to derive rules. We propose a single-pass algorithm for mining linear rules in such a matrix based on...
Quantifiable Data Mining Using Principal Component Analysis (1997)
Faloutsos, Christos, Korn, Flip, Labrinidis, Alexandros, Kotidis, Yannis, Kaplunovich, Alex, Perkovic, Dejan
Association Rule Mining algorithms operate on a data matrix (e.g., customers x products) to derive rules [2,23]. We propose a single-pass algorithm for mining linear rules in such a matrix based on...
Quantifiable Data Mining Using Principal Component Analysis (1997)
Flip Korn, Ros Labrinidis, Yannis Kotidis, Christos Faloutsos, Alex Kaplunovich
Association Rule Mining algorithms operate on a data matrix (e.g., customers \Theta products) to derive rules [2, 22]. We propose a single-pass algorithm for mining linear rules in such a matrix...
Cubetree: Organization of and bulk incremental updates on the data cube (1997)
Nick Roussopoulos, Yannis Kotidis, Mema Roussopoulos
The data cube is an aggregate operator which has been shown to be very powerful for On Line Analytical Processing (OLAP) in the context of data warehousing. It is, however, very expensive to compute,...