Statistical profile estimation in database systems
ACM Computing Surveys (CSUR)
Balancing histogram optimality and practicality for query result size estimation
SIGMOD '95 Proceedings of the 1995 ACM SIGMOD international conference on Management of data
Implementing data cubes efficiently
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
Improved histograms for selectivity estimation of range predicates
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
An overview of data warehousing and OLAP technology
ACM SIGMOD Record
Range queries in OLAP data cubes
SIGMOD '97 Proceedings of the 1997 ACM SIGMOD international conference on Management of data
SIGMOD '97 Proceedings of the 1997 ACM SIGMOD international conference on Management of data
Quasi-cubes: exploiting approximations in multidimensional databases
ACM SIGMOD Record
The ins and outs (and everything in between) of data warehousing
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
Data Cube: A Relational Aggregation Operator Generalizing Group-By, Cross-Tab, and Sub-Total
ICDE '96 Proceedings of the Twelfth International Conference on Data Engineering
Optimal Histograms with Quality Guarantees
VLDB '98 Proceedings of the 24rd International Conference on Very Large Data Bases
Sampling-Based Estimation of the Number of Distinct Values of an Attribute
VLDB '95 Proceedings of the 21th International Conference on Very Large Data Bases
Storage Estimation for Multidimensional Aggregates in the Presence of Hierarchies
VLDB '96 Proceedings of the 22th International Conference on Very Large Data Bases
On the Computation of Multidimensional Aggregates
VLDB '96 Proceedings of the 22th International Conference on Very Large Data Bases
Recovering Information from Summary Data
VLDB '97 Proceedings of the 23rd International Conference on Very Large Data Bases
Optimizing Scientific Databases for Client Side Data Processing
EDBT '02 Proceedings of the 8th International Conference on Extending Database Technology: Advances in Database Technology
Transmitting Datacubes over Congested Networks
ITCC '00 Proceedings of the The International Conference on Information Technology: Coding and Computing (ITCC'00)
An extendible array based implementation of relational tables for multi dimensional databases
DaWaK'05 Proceedings of the 7th international conference on Data Warehousing and Knowledge Discovery
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A number of techniques have been proposed in the literature to optimize the querying of datacubes (i.e., matrix representations of multidimensional relations) in OLAP applications. In this paper we are concerned with the problem of providing very fast executions of range queries on datacubes by possibly returning 'approximate' answers. To this end, given a large datacube with non-negative values for the measure attribute, we propose to divide the datacube into blocks of possibly different sizes and to store a number of aggregate data for each of them (number of tuples occurring in the block, the sum of all measure values, minimum and maximum values). Then, when a range query (in particular, count and sum) is issued, we compute the answer on the aggregate data rather than on the actual tuples, thus returning 'approximated' results. We introduce a number of techniques to perform an estimation (with expected value and variance) of range query answers and compare the accuracies of their estimations. We finally present a comparative analysis with other recently proposed techniques; the results confirm the effectiveness of our approach.