lecture_13.md

Lecture 13

Big data; algorithms

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ETL vs. CI

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Lab 13

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Big-O notation

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Exercise

1. Write out ten two-digit numbers.
2. When I say "go", add them up.
   • Stopwatch
3. Record the time.
   • Results

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For this exercise, don’t care if the answer's right or not.

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1. Form groups of three or four.
2. Someone be the reducer, others will be the workers.
3. Write out ten two-digit numbers, split up among the workers (5-5 or 3-3-4).
4. When I say "go":
   1. Workers:
      1. Add your numbers.
      2. Tell the reducer your sum.
   2. Reducer:
      1. Add them up.
      2. Record the time.

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Takeaways?

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Back to Big-O

Draw chart of times on chalkboard, individual and team

How long would we expect each to take for 100 (10x) numbers?

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Parallelization

• Threads
• Distributed workloads
• MapReduce

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Sync vs. async

What's a real-world example?

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Project Parts 7 and 8