Netezza Rollup Group Aggregates using Grouping sets

The Netezza rollup functionality gives aggregation results at multiple grouping levels in a single result set. In this article, we will check Netezza rollup group aggregates using grouping sets. Netezza Rollup Group Aggregates using Grouping sets You may want to aggregate the records in the tables for each records partition in the group. For examples, consider you want to find out sum of salary of the all employees in the department as a different rows in the query result (row with NULL employee name as highlighted in the image). To…

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Netezza Table Row Size Details

When you create a table in IBM Netezza, the table usually does not take any space on the data slices. Once you insert the rows then only system allocates the space to the rows. In this article, we will see the Netezza table row size details and what are the system columns and their size when you insert rows into the created table. Netezza Table Row Size Details When you insert new row to the created table, IBM Netezza system allocates at least one extent of size 3 MB of…

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Netezza nzsql Query Buffer to Edit Command Line Queries

Life is much easier if you use any query tools to access Netezza nzsql queries. Some people do not like to use specific tool, instead they use Netezza command line. In this article, we will check on Netezza nzsql Query Buffer to edit command line Queries. Netezza nzsql Query Buffer Because the nzsql command is line oriented, it is difficult to edit a complex, multiline SQL statement. Netezza sql supports query buffer that you can use to edit complex and multiline queries. Netezza nzsql Query Buffer Options \e — Edit…

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Netezza nzsql Internal Slash Options

When you use the Netezza nzsql command in interactive mode, there are many options that you can use. These options, known as Netezza nzsql internal slash options, are called with a backslash (\). Many of the internal slash options are the same as those available on the command line. In this article, we will check some of commonly used Netezza nzsql Internal Slash Options. Netezza nzsql Internal Slash Options Following are some commonly used Netezza nzsql internal slash commands: Command Description \? Lists the available internal slash commands. \h Lists…

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Cloudera Impala Performance Tuning Best Practices

When it comes to SQL-on-Hadoop, there are handful frameworks available in market. Hive and Impala are most widely used to build data warehouse on the Hadoop framework. In this article, i will explain you on Cloudera Impala performance tuning best practices. When it comes to SQL-on-Hadoop, there are number of choices available in tools, file formats, schema design, and configurations. Making good design choices when you start is the best way to avoid some of the common mistakes later on. Cloudera Impala Performance Tuning Best Practices Following sections explain you…

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Netezza SQL Query formatter – nz_format and Examples

Sometimes you may have to get the view or any object DDL directly from the Netezza database, in that case you might have noticed that query will not be in proper format. In this article, we will check Netezza SQL query formatter - nz_format with an example. Netezza SQL Query formatter - nz_format You can use the nz_format script functionality to format the Netezza SQL query which is not in proper format. Script will generate the formatted SQL if you pass raw query in form of file or standard input.…

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How to Alter Redshift Table column Data type? Explanation

Amazon Redshift handles petabytes of data without any resource contention. Redshift support many data types to store data into Redshift table. As of now, you can alter Redshift table to increase the size of varchar column. However, Amazon Redshift does not support alter Redshift table column to a different data type for now. This feature may be added in later release for now we will check the alternative to change redshift table column data type. How to Alter Redshift Table column Data type? Currently, there is no way to change…

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Amazon Redshift Distribution Types and Examples

Amazon Redshift is a cluster of nodes with separate disks, memory and CPU. Redshift distributes optimally across all the nodes based on the type of distribution you choose on the table or materialized views. In this article, we will learn about amazon redshift distribution types and some of examples. Amazon Redshift Distribution Types There are three distribution types available in the Amazon Redshift; EVEN, KEY, ALL and AUTO. You can choose any methods based on your requirement and type of joining that you are going to perform on the tables.…

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Netezza find Database Objects – nz_find_object

If you are working on the huge data warehouse and that requires to create thousands of dimension and fact tables in hundreds of databases. You may want search for existence of particular table in hundreds of databases available in Netezza data warehouse appliance, this manual process is time consuming. In this article, we will discuss on Netezza find Database Objects to search the objects. Netezza find Database Objects – nz_find_object Luckily, IBM has provided a script nz_find_object, that can be used to find the objects in Netezza data warehouse appliance.…

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Generate Netezza View DDL using nz_ddl_view

If you are working as a Netezza admin or developer then you may be asked to get DDL or definition of all views available in the particular database. You may have to generate view DDL when you are performing the reverse engineering too. In this article, we will discuss on how to generate Netezza view DDL using nz_ddl_view. Generate Netezza View DDL using nz_ddl_view If you are looking for the tool or script to generate the Netezza DDL or definition, then it might be your lucky day. IBM has provided script…

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