Live Big Data Mock Interview | WALMART | Technical Round | Spark, SQL, Python #interview

I have trained over 20,000+ professionals in the field of Data Engineering in the last 5 years.

𝐖𝐚𝐧𝐭 𝐭𝐨 𝐌𝐚𝐬𝐭𝐞𝐫 𝐒𝐐𝐋? 𝐋𝐞𝐚𝐫𝐧 𝐒𝐐𝐋 𝐭𝐡𝐞 𝐫𝐢𝐠𝐡𝐭 𝐰𝐚𝐲 𝐭𝐡𝐫𝐨𝐮𝐠𝐡 𝐭𝐡𝐞 𝐦𝐨𝐬𝐭 𝐬𝐨𝐮𝐠𝐡𝐭 𝐚𝐟𝐭𝐞𝐫 𝐜𝐨𝐮𝐫𝐬𝐞 - 𝐒𝐐𝐋 𝐂𝐡𝐚𝐦𝐩𝐢𝐨𝐧𝐬 𝐏𝐫𝐨𝐠𝐫𝐚𝐦!

"𝐀 8 𝐰𝐞𝐞𝐤 𝐏𝐫𝐨𝐠𝐫𝐚𝐦 𝐝𝐞𝐬𝐢𝐠𝐧𝐞𝐝 𝐭𝐨 𝐡𝐞𝐥𝐩 𝐲𝐨𝐮 𝐜𝐫𝐚𝐜𝐤 𝐭𝐡𝐞 𝐢𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰𝐬 𝐨𝐟 𝐭𝐨𝐩 𝐩𝐫𝐨𝐝𝐮𝐜𝐭 𝐛𝐚𝐬𝐞𝐝 𝐜𝐨𝐦𝐩𝐚𝐧𝐢𝐞𝐬 𝐛𝐲 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐢𝐧𝐠 𝐚 𝐭𝐡𝐨𝐮𝐠𝐡𝐭 𝐩𝐫𝐨𝐜𝐞𝐬𝐬 𝐚𝐧𝐝 𝐚𝐧 𝐚𝐩𝐩𝐫𝐨𝐚𝐜𝐡 𝐭𝐨 𝐬𝐨𝐥𝐯𝐞 𝐚𝐧 𝐮𝐧𝐬𝐞𝐞𝐧 𝐏𝐫𝐨𝐛𝐥𝐞𝐦."

𝐇𝐞𝐫𝐞 𝐢𝐬 𝐡𝐨𝐰 𝐲𝐨𝐮 𝐜𝐚𝐧 𝐫𝐞𝐠𝐢𝐬𝐭𝐞𝐫 𝐟𝐨𝐫 𝐭𝐡𝐞 𝐏𝐫𝐨𝐠𝐫𝐚𝐦 -

30 INTERVIEWS IN 30 DAYS- BIG DATA INTERVIEW SERIES

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TIMESTAMPS : Questions Discussed
00:00 Introduction
02:05 Project Responsibilities
04:28 Incremental Methodology in CDC Mode
06:46 Scenario based question - SCD
11:23 Ranking Functions in SQL
12:33 Common Table Expressions
13:30 File Formats
15:52 Cache and Persist
17:05 Coding Questions

Music track: Retro by Chill Pulse
Background Music for Video (Free)

Tags
#mockinterview #bigdata #career #dataengineering #data #datascience #dataanalysis #productbasedcompanies #interviewquestions #apachespark #google #interview #faang #companies #amazon #walmart #flipkart #microsoft #azure #databricks #jobs

[gauravmaheshwari]

For the SQL question, an easier approach would be like this:

with cte as(
select machine_id, process_id, max(timestamp)-min(timestamp) as time
from table
group by 1, 2
)

select machine id, average(time) avg_time
from cte
group by 1

[souravdas-ktgg]

sql question approach-
WITH a AS ( SELECT machine_id, process_id, activity_type, timestamp, ROW_NUMBER() OVER (partition by machine_id, process_id ORDER BY machine_id, process_id) AS rn FROM machine),

b as (select a1.machine_id, a1.process_id, a1.activity_type as activity_type1, a1.timestamp as timestamp1,
a2.activity_type as activity_type2, a2.timestamp as timestamp2, (a2.timestamp-a1.timestamp) as timestamp_diff
from a a1 inner join a a2 on a1.machine_id=a2.machine_id and a1.process_id=a2.process_id and a2.rn=a1.rn+1)

select round(avg(timestamp_diff), 3) as avf, machine_id from b group by machine_id order by machine_id;

[sandhyasandy]

Sumit sir please upload the python video it’s been 10 days plz 🙏

[royalkumar]

two approaches for the SQL question which came to my mind ..

SELF JOIN


SELECT
a1.machine_id as machine_id,
round(sum(a2.timestamp - a1.timestamp)/count(distinct(a1.process_id)), 3) as processing_time
FROM Activity a1 INNER JOIN Activity a2
ON a1.machine_id = a2.machine_id AND a1.process_id = a2.process_id
WHERE a1.activity_type = 'start' AND a2.activity_type = 'end'
GROUP BY a1.machine_id ;

CASE STATEMENT


SELECT
machine_id,
round(sum(case when activity_type = 'start' then -timestamp else timestamp end )/count(distinct(process_id)), 3)as processing_time
from Activity
group by machine_id ;

[hdr-tech]

Reverse string on every occurrence of I letter
Avg of logged time

[shubhamyadav-vdgv]

Nice discussion, but we can't say it's data engineer mock interview.

[vaibhavverma]

My Approach python Coding Question -

s = "stringity"

i = 0
res = ""
for str in range(len(s)):
if s[str] == 'i':
res += s[i:str][::-1]
i = str+1

print(res+s[i:])

[SenthilKumarBDE]

First view, first like, first comment. 🎉

[laxmipoojamule]

Yes sir please upload python videos we r waiting from long