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Showing posts from May, 2018

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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

HBASE: Top Features in Storing Big data

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In this post explained top features added in HBase to handle the data. The Java implementation of Google's Big Table you can call it as HBASE.  In HBase, the data store as two parts. Row Key : 00001 Column : (Column Qualifier:Version:Value) Features of HBASE HBase data stores consist of one or more tables, which are indexed by row keys. Data is stored in rows with columns, and rows can have multiple versions. By default, data versioning for rows is implemented with time stamps. Columns are grouped into column families, which must be defined upfront during table creation. Column families are stored together on disk, which is why HBase is referred to as a column-oriented datastore New features of HBASE check now In addition... HBase is a distributed data store, which leverages a network-attached cluster of low-cost commodity servers to store and persist data. HBase architecture is a little trick to know. Region Servers... RegionServers are the software p

Python: How to Write Logic to Print Triangle

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Here's an example to print Triangle in Python. It's the best interview question. You can expect this type of question in your interview. So this is useful to practice it. How to Print Triangle Logic to Print Trianagle max = 8 for x in range(1, max + 1): for y in range(1, x + 1): print y, print Result 1 1 2 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5 6 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8   Also, Read Python while loop Python for loop example