BigData

Basic Hadoop HDFS Filesystem Operations With Examples

There are many interfaces to HDFS available, but the command line (CLI) is one of the simplest and, to many developers, the most familiar interface. You can perform most advanced and basic Hadoop HDFS filesystem operations using CLI. Basic Hadoop HDFS Filesystem Operations The when Hadoop HDFS filesystem is set, you can do all of the basic HDFS filesystem operations, such as reading files, creating directories, moving files, deleting data, and listing directories. You can also perform the advance Hadoop HDFS filesystem operations such as updates, administrator from command line.…

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October 31, 2016
BigData

Hadoop HDFS Schema Design for ETL Process

Now a day’s many organisations are using Hadoop for their ETL processing. In this post we will learn Hadoop HDFS Schema Design for ETL Process. In this section, you will learn about good schema design for data that you store in Hadoop HDFS directly. Hadoop HDFS Schema Design Overview Many organisation uses Hadoop for storing and processing unstructured, semi-structured or structured data. Hadoop is schema-on-read model that does not impose any requirements when loading data into Hadoop ecosystem. You can simply ingest data into Hadoop HDFS by using available ingestion…

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October 26, 2016
BigData

Hadoop Data Warehouse and Design Considerations

A data warehouse, also known as an enterprise data warehouse (EDW), is a large collective store of data that is used to make such data-driven decisions, thereby becoming one of the centrepiece of an organization’s data infrastructure. Hadoop Data Warehouse was challenge in initial days when Hadoop was evolving but now with lots of improvement, it is very easy to develop Hadoop data warehouse Architecture. This article will server as a guide to Hadoop data warehouse system design. Hadoop data warehouse integration is now a days become very much popular…

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October 26, 2016
Netezza

Netezza Backup and Restore: Best Practices

In this post you will learn about Netezza backup and restore data. It provides general information on backup and restore methods available with Netezza system. Netezza Backup and Restore Overview Netezza provides several backup and restore methods as per the different requirements. You can take table or database backup whenever required: You can create full and incremental backups of your various Netezza databases in compressed internal using the nzbackup command and restore them to a Netezza system whenever required using nzrestore command. As a best practice create script that perform…

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October 25, 2016
Netezza

Netezza Pad Zero with Working Example

Netezza pad zero functions are string functions used to remove or add the string to beginning or end of the expression. An expression could be column values. There are two pad functions available in Netezza; LPAD and RPAD string functions. You can use those function in Netezza pad zero or any other character provided in arguments: Read: Netezza String Functions and Usage Different types of Netezza Trim Functions and Examples Netezza Date Functions and Examples nzsql Command and its Usage Netezza LPAD function You can use this function to pad string…

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October 24, 2016
Netezza

Netezza Export Table Data to CSV format

You can export the Netezza table in many ways. Netezza export table is done using either Netezza external table or Netezza nzsql commands. Use of Netezza external table is fastest way to export Netezza table data compared to a Netezza nzsql command. Netezza nzsql with option -o is easy method compared to creating Netezza external tables. Netezza Export Table using Netezza External Tables You can use the Netezza transient external table to export the data table to flat file (CSV format). This feature is very handy if you are exporting…

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October 21, 2016
Netezza

Netezza MERGE command to Manipulate Records from Table

Use the Netezza MERGE command to insert, update, or delete rows in a target table using data from a source such as a table, view, or sub-query and based on rules specified for a matching condition in the merge statements. In the Netezza merge command, you must specify at least one matching_condition statement to identify the rows that you want to update, insert or delete. This feature is not supported in all versions of Netezza. IBM has introduced this feature in Netezza 7.2.1 or higher. MEGRE command is used to…

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October 20, 2016
Netezza

Netezza Temporary Tables and Examples

Like any other database, Netezza also supports temp or temporary tables. There are three types of Netezza temporary tables; all of them have advantage over traditional temporary tables. Netezza Temporary Tables Netezza temporary tables are local to the user session. You can use temporary table repeatedly within a user session for multiple times. Like derived tables, temporary tables also use Netezza swap partition space. You can drop and recreate the temporary table within the user session. However, these temporary tables are not visible outside the user session. You do not…

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October 19, 2016
Netezza

Netezza Query Tool Introduction, Features and Screenshot

Netezza supports JDBC, ODBC and OLEDB connectors. There are many free and paid Netezza query tool available in market. There most popular Netezza query tool includes Aginity workbench, WinSQL, SQuirrel SQL Client tool etc. Aginity Workbench Aginity Workbench is free, most popular and an easy-to-use application that enhances your performance when you are working with your Netezza data warehouse. If anybody think of Netezza query tool then first thing comes to their mind is Aginity workbench. This SQL database development tool offers unique capabilities that allow you to focus on…

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October 18, 2016
BigData

Cloudera Impala Truncate Table Statement Examples

Cloudera Impala TRUNCATE TABLE statement removes all records from the table while keeping the table structure as it is. This statement is low overhead alternative for dropping and re-creating the tables. This statement is also low overhead compared to the INSERT OVERWRITE to replace the existing data from the HDFS directory before copying data. This is one of the features added in CDH 5.5 or higher. This statement helps when you are performing ELT/ELT operation cycles on Cloudera Impala where you have to empty the table after the data has…

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October 17, 2016