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18 SQL best practices interview Q&As

#1. Use uppercase for the keywords like SELECT, FROM, JOIN, GROUP BY, WHERE, etc. It’s also a good practice to use uppercase for the SQL functions like UPPER(col_name),

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What does this Unix code snippet do?

Data Engineers & Java Developers must have a good handle on Unix. Most production systems are Linux based with 1000’s of scripts.

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Q01. What does the below Unix code do?

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00: 13 Data Warehouse interview Q&As – Fact Vs Dimension, CDC, SCD, etc – part 2

This extends Q1 to Q5 at 13 Data Warehouse interview Q&As – Fact Vs Dimension, CDC, SCD, etc – part 1. Q6. … Read more ›...



11D: Scala existential type interview Q&As

Q01. What are existential types? A01. Existential types are a way of abstracting over types. They let you assert that some type “exists” without specifying exactly what it is as...



23: Scala Traits, Mixins, self-type annotation & DI with Cake pattern

Q01. What is a trait in Scala? A01. In Scala, trait is a collection of abstract and non-abstract methods. You can create trait that can have all abstract methods or...



Apache Spark SQL join types interview Q&As

Q1. What are the different Spark SQL join types?
A1. There are different SQL join types like inner join, left/right outer joins, full outer join,

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Spark interview Q&As with coding examples in Scala – part 11: add column values conditionally, lit & typedlit

This extends Spark interview Q&As with coding examples in Scala – part 10: adding new columns. Q01. How will you add a new column with a fixed value? … Read...



Spark interview Q&As with coding examples in Scala – part 10: adding new columns

This covers one of the most popular Spark interview questions of adding new columns to Spark Dataframes. Most non-trivial Spark jobs will have additional columns added to an existing Dataframe.

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40+ Apache Spark best practices & optimisation interview FAQs – part 03: Partitions & buckets

#31 Bucketing is another data optimisation technique that groups data with the same bucket value across a fixed number of “buckets”. Bucketing improves performance in wide transformations and joins by...



02B: Scala FP basics: Explain the below Scala code

Q. Can you explain the concepts used in the below code? Output: A. The above code runs the function “(x:Int) =x + 2” … Read more ›...



11C: Q73 – Q77 – Scala type parameterization & variance interview Q&As

This extends the type parameters basics at 11B: Q71 – Q72 – Scala type parameterization & variance interview Q&As. Cage[T] T is of any type Invariance Cage[T <: Animal] T...



13A: Scala Semigroup interview Q&As

Semigroups, Monoids, Functors, Monads, Applicatives, etc are concepts or patterns that abstract complexities in computations, and NOT traits or classes. You can think of them as type classes like List[T],...



17: Coding Scala Way – What is wrong with this code?

Q. What is wrong with the below code? How will you fix it?

A. The above code will always return “false”.

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800+ Java Interview Q&As

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