Results 1 - 10 of 294

Ripple Joins for Online Aggregation

by Peter J. Haas, Joseph M. Hellerstein
"... We present a new family of join algorithms, called ripple joins, for online processing of multi-table aggregation queries in a relational database management system (dbms). Such queries arise naturally in interactive exploratory decision-support applications. Traditional offline join algorithms are ..."
Abstract - Cited by 188 (11 self) - Add to MetaCart
We present a new family of join algorithms, called ripple joins, for online processing of multi-table aggregation queries in a relational database management system (dbms). Such queries arise naturally in interactive exploratory decision-support applications. Traditional offline join algorithms

Processing data-stream join aggregates using skimmed sketches

by Sumit Ganguly, Minos Garofalakis, Rajeev Rastogi - In Proc. Int. Conf. on Extending Database Technology (EDBT , 2004
"... sganguly,minos,rastogi¡ Abstract. There is a growing interest in on-line algorithms for analyzing and querying data streams, that examine each stream element only once and have at their disposal, only a limited amount of memory. Providing (perhaps approximate) answers to aggregate queries over such ..."
Abstract - Cited by 23 (4 self) - Add to MetaCart
size of two streams. (Our techniques also readily extend to other join-aggregate queries.) To the best of our knowledge, our skimmed-sketch technique is the first comprehensive join-size estimation algorithm to provide tight error guarantees while: (1) achieving the lower bound on the space required

Improved unnesting algorithms for join aggregate SQL queries

by M. Muralikrishna - In Proc. Int. Conf. on Very Large Data Bases (VLDB , 1992
"... Abstract: The SQL language allows users to express queries that have nested subqueries in them. Optimi-zation of nested queries has received considerable attention over the last few years [Kim82, Ganski87, Daya187, Murali891. As pointed out in [Ganski87], the solution presented in [Kim821 for JA typ ..."
Abstract - Cited by 46 (0 self) - Add to MetaCart
. In addition, we present a couple of enhancements that precompute aggregates and evaluate joins and outer joins in a top-down order. These enhancements eliminate Cartesian products when certain correlation predicates are ab-sent and enable us to employ Kim’s method for more blocks. Finally, we incorporate

Join synopses for approximate query answering

by Swarup Acharya, Phillip B. Gibbons, Viswanath Poosala, Sridhar Ramaswamy - In SIGMOD , 1999
"... In large data warehousing environments, it is often advantageous to provide fast, approximate answers to complex aggregate queries based on statistical summaries of the full data. In this paper, we demonstrate the difficulty of providing good approximate answers for join-queries using only statistic ..."
Abstract - Cited by 169 (9 self) - Add to MetaCart
In large data warehousing environments, it is often advantageous to provide fast, approximate answers to complex aggregate queries based on statistical summaries of the full data. In this paper, we demonstrate the difficulty of providing good approximate answers for join-queries using only

The Gamma database machine project

by David J. Dewitt, Shahram Ghandeharizadeh, Donovan Schneider, Allan Bricker, Hui-i Hsiao, Rick Rasmussen - IEEE Transactions on Knowledge and Data Engineering , 1990
"... This paper describes the design of the Gamma database machine and the techniques employed in its implementation. Gamma is a relational database machine currently operating on an Intel iPSC/2 hypercube with 32 processors and 32 disk drives. Gamma employs three key technical ideas which enable the arc ..."
Abstract - Cited by 272 (29 self) - Add to MetaCart
to describing the design of the Gamma software, a thorough performance evaluation of the iPSC/2 hypercube version of Gamma is also presented. In addition to measuring the effect of relation size and indices on the response time for selection, join, aggregation, and update queries, we also analyze

, Minos Garofalakis

by Arnon Lazerson, Izchak Sharfman, Daniel Keren, Assaf Schuster, Vasilis Samoladas
"... Emerging large-scale monitoring applications rely on continuous tracking of complex data-analysis queries over collections of mas-sive, physically-distributed data streams. Thus, in addition to the space- and time-efficiency requirements of conventional stream pro-cessing (at each remote monitor sit ..."
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as the covering spheres method. We analyze our approach and demonstrate its effectiveness for the important case of sketch-based approximate tracking for norm, range-aggregate, and join-aggregate queries, which have numerous applications in streaming data analysis. Experimental results on real-life data streams

Join Algorithms for Online Aggregation

by Peter J. Haas, Peter J. Haas, Joseph M. Hellerstein, Joseph M. Hellerstein - IBM Research Report RJ 10126, IBM Almaden Research , 1998
"... : We provide a new family of join algorithms, called ripple joins, for online processing of complex, multi-table aggregation queries in a relational database management system (dbms). Such queries arise naturally in interactive exploratory decision-support applications. As opposed to traditional off ..."
Abstract - Cited by 6 (3 self) - Add to MetaCart
: We provide a new family of join algorithms, called ripple joins, for online processing of complex, multi-table aggregation queries in a relational database management system (dbms). Such queries arise naturally in interactive exploratory decision-support applications. As opposed to traditional

Aggregate Skyline Join Queries: Skylines with Aggregate Operations over Multiple Relations

by Arnab Bhattacharya , B Palvali Teja - In COMAD , 2010
"... Abstract The multi-criteria decision making, which is possible with the advent of skyline queries, has been applied in many areas. Though most of the existing research is concerned with only a single relation, several real world applications require finding the skyline set of records over multiple ..."
Abstract - Cited by 3 (0 self) - Add to MetaCart
such queries as "aggregate skyline join queries". Since the naïve algorithm is impractical, we propose three algorithms to efficiently process such queries. The algorithms utilize certain properties of skyline sets, and processes the skylines as much as possible locally before computing the join

Including Group-By in Query Optimization

by Surajit Chaudhuri, Kyuseok Shim , 1994
"... In existing relational database systems, processing of group-by and computation of aggregate functions are always postponed until all joins are performed. In this paper, we present transformations that make it possible to push group-by operation past one or more joins and can potentially reduce the ..."
Abstract - Cited by 121 (6 self) - Add to MetaCart
In existing relational database systems, processing of group-by and computation of aggregate functions are always postponed until all joins are performed. In this paper, we present transformations that make it possible to push group-by operation past one or more joins and can potentially reduce

Abstract Ripple Joins for Online Aggregation

by Peter J. Haas, Joseph M. Hellerstein
"... We present a new family of join algorithms, called ripple joins, for online processing of multi-table aggregation queries in a rela-tional database management system (DBMS). Such queries arise naturally in interactive exploratory decision-support applications. Traditional offline join algorithms are ..."
Abstract - Add to MetaCart
We present a new family of join algorithms, called ripple joins, for online processing of multi-table aggregation queries in a rela-tional database management system (DBMS). Such queries arise naturally in interactive exploratory decision-support applications. Traditional offline join algorithms
Results 1 - 10 of 294