Map reduce advantages over parallel databases

Map reduce advantages over parallel databases

• 1.
  M a pR e d u c e a d va n t a g e s o ve r p a r a l l e l d a t a b a s e s MAPREDUCE 1
• 2.
  Outline • Introduction • HeterogeneousSystems • Complex Functions • Fault Tolerance • Performance • Conclusion 2
• 3.
  MapReduce: A FlexibleData Processing Tool • Map Reduce is a programming model MapReduce is composed of : • Map function key/value pairs • Reduce function key/values • Processes many terabytes of data • System easy to use 3
• 4.
  Paper • By AndrewPavloetal • Comparison paper • MapReduce is a major step backwards 4
• 5.
  Heterogeneous Systems • MapReduceprovides a simple model for analyzing data in such heterogeneous systems • Storage systems like relational database or file systems • In parallel database : • input must be copied • then analyze 5
• 6.
  Complex Functions • Map& Reduce functions are simple and straight forward SQL equivalent. • Pavloetal pointed that some times it very complicated to be expressed in SQL • User Defined Functions(UDFs) • Buggy some times • MapReduce is a better framework 6
• 7.
  Fault Tolerance (1/2) •Two models to transfer data between mappers and reducers: • Pull model (move) • Push model (write) • Pull model create many files and disks (Pavloetal ) • MapReduce used : • batching, sorting and grouping • Smart scheduling for reads 7
• 8.
  Fault Tolerance (2/2) •MapReduce do not use push model due to fault- tolerance • Fault tolerance will be more important to process these data efficiently. 8
• 9.
  Performance (1/2) • Mergingresults (cost) : • Merging isn’t necessary when the next consumer of MapReduce is: • another MapReduce • not another MapReduce 9
• 10.
  Performance (2/2) • Dataloading: • Hadoop can analyze data 5 to 50 times faster than the time needed to load data to parallel database 10
• 11.
  Conclusion • MapReduce isa highly effective and efficient tool for large-scale fault-tolerant data analysis • MapReduce is very useful in a heterogeneous system • MapReduce provides a good framework 11