Details about bigdata

BigData

Hive Create View Syntax and Examples

You can use Hive create view to create a virtual table based on the result-set of a complex SQL statement that may have multiple table joins. The CREATE VIEW statement lets you create a shorthand abbreviation for a more complex and complicated query. Apache Hive view is purely a logical construct (an alias for a complex query) with no physical data behind it. Note that, Hive view is different from lateral view.  Read: Hive CREATE INDEX to Optimize and Improve Query Performance Hadoop Hive Bucket Concept and Bucketing Examples Hive…

Continue ReadingHive Create View Syntax and Examples
Comments Off on Hive Create View Syntax and Examples
November 11, 2017
BigData

Access HBase Tables from Impala working Examples

As you know Hadoop Hive or Impala does not properly support transaction data. HBase is best suited for the table which required lot of delete, update, insert etc. You may want to explore the data stored in the HBase table. This article, helps you to understand how to access HBase tables from Impala and we will check out process with an example. Read other article on loading HBase table from Hive: Loading HBase Table from Apache Hive Why you want to access the HBase tables from Impala? This is obvious…

Continue ReadingAccess HBase Tables from Impala working Examples
Comments Off on Access HBase Tables from Impala working Examples
November 8, 2017
BigData

Cloudera Impala Type Conversion Functions and Examples

Impala has some very strict rules regarding data types for function parameters that you provide while executing it. Impala type conversion functions are used to explicitly convert the required format. For example, Impala does not convert DOUBLE to FLOAT, INT to STRING etc. In my other post, we have discussed on Impala date functions and examples. In this article, we will check out Cloudera Impala type conversion functions with an examples. Read: Commonly used Cloudera Impala Date Functions and Examples Impala Type Conversion Functions These type conversion functions uses common…

Continue ReadingCloudera Impala Type Conversion Functions and Examples
Comments Off on Cloudera Impala Type Conversion Functions and Examples
November 8, 2017
BigData

Clouderal Impala SQL Join Types and Examples

Impala SQL Join is a clause that is used for combining specific fields from two or more tables based on the common columns. The joins in the Impala are similar to the SQL and Hive joins. Joins are used to combine rows from multiple tables. In this article, we will learn about different Impala SQL join types with examples. Different Impala Join Types Following are Different Hive Join Types INNER JOIN LEFT OUTER JOIN RIGHT OUTER JOIN FULL OUTER JOIN SEMI JOIN ANTI JOIN CROSS JOIN Below are the tables…

Continue ReadingClouderal Impala SQL Join Types and Examples
Comments Off on Clouderal Impala SQL Join Types and Examples
November 7, 2017
BigData

Hadoop – Export Hive Data with Quoted Values into Flat File and Example

In general, quoted values are values which are enclosed in single or double quotation marks. Usually, quoted values files are system generated where each and every fields in flat files is either enclosed in SINGLE or DOUBLE quotation mark. In this article, we will check how to export Hadoop Hive data with quoted values into flat file such as CSV file format. Quoted Value File Overview In the quoted values files, values are enclosed in quotation mark in case there is a embedded delimiter. For example, comma separated values file…

Continue ReadingHadoop – Export Hive Data with Quoted Values into Flat File and Example
Comments Off on Hadoop – Export Hive Data with Quoted Values into Flat File and Example
November 5, 2017
BigData

Hadoop Security – Hadoop HDFS File Permissions

Hadoop HDFS file permissions are almost similar to the POSIX file system. In a Linux system, we usually create OS level users and make them members of an existing operating system group. But in Hadoop, we create directory and associate it with an owner and a group. Hadoop HDFS File and Directory Permissions The following sections show Hadoop HDFS file and directory permissions: Just like Linux operating system, Hadoop uses notation (r,w) to denote read and write permissions. There is an execute (x) permission for files but you cannot execute…

Continue ReadingHadoop Security – Hadoop HDFS File Permissions
Comments Off on Hadoop Security – Hadoop HDFS File Permissions
November 2, 2017
BigData

Migrating Netezza Data to Hadoop Ecosystem and Sample Approach

In my other post ‘Migrating Netezza to Impala SQL Best Practices’, we have discussed various best practices to migrate the Netezza SQL scripts to Impala SQL. In this article, we will discuss steps on Migrating Netezza Data to Hadoop Ecosystem. Migrating Netezza Data to Hadoop Ecosystem – Offload Netezza data to Hadoop HDFS Now a days Hadoop ecosystem is gaining popularity and organization with huge data wants to migrate to Hadoop ecosystem for their faster analytics that includes real-time or near real-time. Steps to Migrating Netezza Data to Hadoop Ecosystem…

Continue ReadingMigrating Netezza Data to Hadoop Ecosystem and Sample Approach
2 Comments
October 30, 2017
BigData

Hive Create External Tables and Examples

A Hive external table allows you to access external HDFS file as a regular managed tables. You can join the external table with other external table or managed table in the Hive to get required information or perform the complex transformations involving various tables. In this article, we will check on Hive create external tables with an examples. You have to create external table same as if you are creating managed tables. LOCATION is mandatory for creating external tables. LOCATION indicates the location of the HDFS flat file that you want…

Continue ReadingHive Create External Tables and Examples
Comments Off on Hive Create External Tables and Examples
October 26, 2017
BigData

Hadoop Hive Create, Drop, Alter, Use Database Commands and Examples

Hadoop Hive is database framework on the top of Hadoop distributed file systems (HDFS) developed by Facebook to analyze structured data. It supports almost all commands that regular database supports. Hadoop hive create, drop, alter, use database commands are database DDL commands. This article explains these commands with an examples. Hive contains a default database named default. Read: Hive Create External Tables and Examples Hadoop Hive SHOW DATABASES commds This command displays all the databases available in Hive. Below is the example of using show database command: hive> show databases;…

Continue ReadingHadoop Hive Create, Drop, Alter, Use Database Commands and Examples
Comments Off on Hadoop Hive Create, Drop, Alter, Use Database Commands and Examples
October 12, 2017
BigData

Hive Create Table Command and Examples

The syntax of creating a Hive table is quite similar to creating a table using SQL. In this article explains Hive create table command and examples to create table in Hive command line interface. You will also learn on how to load data into created Hive table. Hive Create Table Command Hive Create Table statement is used to create table. You can also create the table hive while importing data using Sqoop command. To use, Sqoop create Hive table command, you should specify the --create-hive-table option in Sqoop command. You…

Continue ReadingHive Create Table Command and Examples
Comments Off on Hive Create Table Command and Examples
October 11, 2017