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Showing posts from September, 2016

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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

13 Cloud Computing Terminology Quick Read

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Cloud computing is a big ocean. Due to increased services, a developer must know the glossary ( keywords) involved. 1) AWS Amazon Web services 2) Content delivery network (CDN) It is a distributed system. Servers are located in remote locations. Customers feel that they are accessing the servers. 3) Cloud A global network to access the resources. 4) Cloud portability The feature to move data from one Cloud provider to another provider. 5)  Cloudsourcing Moving traditional IT operations to Cloud computing. 6) Cloud storage It is a service providing to users to store data using the internet or other private networks. 7) Cloudware It is Software that helps to run user applications in cloud computing. Terminology 8) Cluster A group of small computers connected together to form a Single big computer. High availability and load balancing are the main benefits. 9) Consumer cloud The cloud provider offers services to individual users. You can call it a consumer cloud. 10) Consumption-bas

Python String Comparison Top Ideas

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In Python, you can compare two strings how you would do on numbers. Python is stricter on string comparison. It identifies any small differences in strings. So Python is case sensitive while comparing it checks for identical ones.    Python follow-suite other languages. It compares strings for exact equals. Else, treat them as different strings. Python String Comparison  Extra spaces Uppercase or Lowercase #1 Example >>> a = " V irginia" >>> b = " v irginia" >>> a == b False  The strings a and b are looking similar. But there is case sensitive difference. Python checks for extra white spaces as well as Upper or Lowe case letters. #2 Example >>> greet1 = "Hello " >>> greet2 = "Hello" >>> greet1   == greet2 False The greet1 has space at the end whereas greet2 does not. Python looks at whitespace when comparing strings, so the two aren’t considered equal.