1,353 research outputs found
Sorting Technique- An Efficient Approach for Data Mining
As the new data or updates are arriving constantly, it becomes very difficult to handle data in an efficient manner. Moreover, if data is not refreshed it will soon become of no use. Hence data should be updated on regular mode so that it do not obsolete in coming future. In traditional work several other approaches or methods like page ranking, i2mapreduce( that is extension of Map Reduce) were used to enhance performance and increase computation speed as well as run-time processing. But as we have seen the performance is not up to that level which is required in current environment. So, to overcome these drawbacks, in this paper sorting technique is proposed that can enhance mean value and overall performance
Approximation with Error Bounds in Spark
We introduce a sampling framework to support approximate computing with
estimated error bounds in Spark. Our framework allows sampling to be performed
at the beginning of a sequence of multiple transformations ending in an
aggregation operation. The framework constructs a data provenance tree as the
computation proceeds, then combines the tree with multi-stage sampling and
population estimation theories to compute error bounds for the aggregation.
When information about output keys are available early, the framework can also
use adaptive stratified reservoir sampling to avoid (or reduce) key losses in
the final output and to achieve more consistent error bounds across popular and
rare keys. Finally, the framework includes an algorithm to dynamically choose
sampling rates to meet user specified constraints on the CDF of error bounds in
the outputs. We have implemented a prototype of our framework called
ApproxSpark, and used it to implement five approximate applications from
different domains. Evaluation results show that ApproxSpark can (a)
significantly reduce execution time if users can tolerate small amounts of
uncertainties and, in many cases, loss of rare keys, and (b) automatically find
sampling rates to meet user specified constraints on error bounds. We also
explore and discuss extensively trade-offs between sampling rates, execution
time, accuracy and key loss
- …