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SQL Interview Success: Unlocking the Top 5 Frequently Asked Queries

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 Here are the five top commonly asked SQL queries in the interviews. These you can expect in Data Analyst, or, Data Engineer interviews. Top SQL Queries for Interviews 01. Joins The commonly asked question pertains to providing two tables, determining the number of rows that will return on various join types, and the resultant. Table1 -------- id ---- 1 1 2 3 Table2 -------- id ---- 1 3 1 NULL Output ------- Inner join --------------- 5 rows will return The result will be: =============== 1  1 1   1 1   1 1    1 3    3 02. Substring and Concat Here, we need to write an SQL query to make the upper case of the first letter and the small case of the remaining letter. Table1 ------ ename ===== raJu venKat kRIshna Solution: ========== SELECT CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS capitalized_name FROM Table1; 03. Case statement SQL Query ========= SELECT Code1, Code2,      CASE         WHEN Code1 = 'A' AND Code2 = 'AA' THEN "A" | "A

5 Tricky Python Interpreter Interview Questions

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Python is an interpreter, which converts to byte-code when it first encounters the .py module. It is portable. And, it is a one-time job. IN THIS PAGE Python Interpreter Interview Questions Python Interpreter 1 - What's an Interpreter? Python interpreter  converts source-code to byte-code when you first execute it is non-runnable code. The only software can process that code. During Python installation, a virtual environment will create. This environment can parse the byte code. 2 - What're the differences Between Bytecode and Machine Code? Machine code is binary that you can see in the form of 0,1s. Byte code is non-readable, only a designated software can parse it. 3 - How does Python Interpreter Work? Self-read flow chart. The smiley is byte-cod e. It uses other libraries and create byte-code. Execution flow of Interpreter 4 - When you Install Python, the list of components do you think to install? Interpreter and Libraries. Interpreter. The process of the interpreter is Bla

Top Hadoop Architecture Interview Questions

The hadoop.apache.org web site defines Hadoop as "a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models." Quite simply, that's the philosophy: to provide a framework that's simple to use, can be scaled easily, and provides fault tolerance and high availability for production usage. The idea is to use existing low-cost hardware to build a powerful system that can process petabytes of data very efficiently and quickly. More : Top selected Hadoop Interview Questions Hadoop achieves this by storing the data locally on its DataNodes and processing it locally as well. All this is managed efficiently by the NameNode, which is the brain of the Hadoop system. All client applications read/write data through NameNode. Hadoop has two main components: the Hadoop Distributed File System (HDFS) and a framework for processing large amounts of data in parallel using the MapReduce paradigm HDFS

Data analysis report these are example queries to use on final data

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ApplyAnalytics@twitter The role of data analysis will come into picture, once you have cleaned and filter the raw unstructured data. The next stage is called analysis. Your success of data analysis project is based preparing highly informative final report. Tip:  What could you investigate with data To prepare analysis report, you need to ask some intelligent questions. These are example questions you can use. Based on your questions, you  need to prepare SQL queries to get the desired report or dashboard from your final data or cleaned data.  The report or dashboard should be such that it should improve client business. Let us use some case study on world bank data, what are the questions come into mind:  How much (in USD) is spent on healthcare in total in each country?  How much (in USD) is spent per capita in each country?  In which country is the most spent per person?  In which country is the least spent?  What is the average for each