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adrien.wattez_188697 avatar image
adrien.wattez_188697 asked greg.joshua_21724 commented

Can I get the solution for the Read Techniques unit of the DS220 Academy course?

HI,

Is it possible to provide solution for READ TECHNIQUES section in DS220 6.x course.

I checked pdf solutions but i didn't find any solution for this section.

I need to check some part, I don't have same number of rows on Materialized view etc.

Thanks

academyds220
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2 Answers

smadhavan avatar image
smadhavan answered

@adrien.wattez_188697, Read Techniques section of DS220 has the following 4 exercise sections and which one are you looking for in particular?

  1. Exercise 5.1: Creating Secondary Indexes
  2. Exercise 5.2: Creating Materialized Views
  3. Exercise 5.3: Implementing Aggregation In Your Data Model
  4. Exercise 5.4: Using the Cast Function

The DS220 Exercises zip actually contains solutions for a couple of them like 5.3. You could also refer to the following resources for additional details for each topic,

  1. Using secondary indexes
  2. Using Materialized Views
  3. Aggregation & its usage in SELECT statement
  4. Using cast scalar function

Hope that helps!

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rashmisingh avatar image
rashmisingh answered greg.joshua_21724 commented

@adrien.wattez_188697, the videos.csv file from the zip has the same user_id for all the records, which is different from the user_id used in the exercise. Maybe that is the problem you are facing as well.


Here is what I have-

final $ pwd
~/DS220/labwork/final
final $ awk -F, '{print $NF}' videos.csv  | uniq
user_id
63d97ca8-4630-4bad-805f-3bda997f3dcc
final $


Hope this helps!

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greg.joshua_21724 avatar image greg.joshua_21724 commented ·

@rashmisingh that is exactly the issue. There is only one user_id value and it does not match the value that the exercise says should return 13 rows. The exercise material is not in sync with the actual data.

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