Live Azure Data Engineering Mock Interview | Technical Round | Out of Memory Issue | SQL

[@imranhossain1660]

Delta table maintains history with the help of transaction lo files which are in json format. This log files helps delta table to maintain different table snapshot version, time travel feature and maintain ACID property. As we know concurrent read and write opearions is possible in delta tabel by the log files. The actual data is stored in delta table stored in parquet format. Over the time it geneerates so much small data files and to comapct the smaller files we can use optimize and zorder command on delta table. The VACUUM command in Delta Lake is used to remove old data files that are no longer accessible from the current state of the table and are beyond the retention period and not part of the latest snapshot version of delta table.

[@solondas96]

Great explanation ❤

[@imranhossain1660]

@@solondas96 Thank you

[@divakarjona7603]

Data Engineer interview series helping a lot. Please make videos on GCP as well. Thanks.

[@dipakchavan4659]

This Mock interviews series is really good, but how do we know that candidates attending interview is anwering correctly or not. If he or she answers wrong then how do we know?

[@abhishekmohanty9971]

Just my suggestion, dont look for correct answers in interview. If you know the answer already then you know whether its wrong or correct. If you dont know then i would suggest please read on that topic because you will not get complete picture even if the interviewee is correct. Just look how the interviwee is approaching the questions even to the unknown questions plus what kind of questions are being asked. I hope your query is aptly answered.

[@solondas96]

Aptly explained abhishek. Mock interviews are mostly to test a candidate’s approach to a certain problem. In an interview there is no complete right or wrong answer. It basically tests on the candidates ability to hold their composure and try their best to reach the solution to the question asked. Let me know if you want to know all the correct answer to the questions i have asked. I would post it in the comments section for your reference. 😊 Happy Learning