Interview Questions list

Q1: Hive schema
Answer:
hive> CREATE SCHEMA userdb;

Q2: Hive ORC and Hive ETL
Answer:
ORC <The Optimized Row Columnar> file format provides a highly efficient way to store Hive data. It was designed to overcome limitations of the other Hive file formats. Using ORC files improves performance when Hive is reading, writing and processing data.

Hive ETL : Example: How to use Hive for ELT

Q3: MongoDB and JSON format
Answer:
Storing JSON data from Java/ Node.js to MongoDB

Q4: Java finally
Answer:
The finally block always execute in Java

Q5: Time complexity of recursive implementation

Integer foo( Integer a, Integer b) {
    return a == 0 ? foo(a - 1, b) + b;
}

Answer:
Time complexity should be O (n^2) because the function computes the sum 1 + 2 + ... + n
n+1 <which is n/2.>

Q6: Shell Script: print the third word in the third line of each file under the folder
Answer:

#!/bin/bash
#!/bin/sh  
#============ Print 3rd word in 3rd line under the folder ===========  
Folder_A="./"  
Output_file="output.txt"
for file in ${Folder_A}/*.log; do  
    filename=`basename $file`  
    awk 'NR==3 {print$3}' $filename
    awk 'NR==3 {print$3}' $filename >> $Output_file
done     
## Result
#huazhang@huas-MacBook-Pro Macys (master) $ ./PrintWordInLineShell.sh
#system
#FTP

Q7. Scala question: convert lists to list of tuple
Answer:

scala> val lists = List(((1,52),7), ((1,82),6))
lists: List[((Int, Int), Int)] = List(((1,52),7), ((1,82),6))

scala> lists map { case ((a,b),c ) => (a,b,c) }
res7: List[(Int, Int, Int)] = List((1,52,7), (1,82,6))