Netezza

How to Resolve Netezza too many Concurrent Sessions issue?

If you are working on the Netezza with the heavy load on it then you might have seen the Netezza too many concurrent sessions issue when you try to connect to the Netezza system. You may get this issue while connecting to Netezza from Aginity workbench or from Putty. In this article, we will see how to resolve Netezza too many concurrent session issue. Check Netezza too many Concurrent Sessions issue To verify the concurrent sessions follow below steps: Login to Netezza either from Putty or from Aginity Workbench and…

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June 1, 2017
Netezza

How to Find Netezza Table Size?

There are two ways to identify the size of table in Netezza. One, query the Netezza system tables and get the table size. Second, use the Netezza admin tool to check table size. In this article, we will discuss on how to find Netezza table size using Netezza nzsql and Netezza admin tools. More Readings: Netezza system tables and views Netezza nzsql command and its usage How to install Aginity workbench for Netezza? How to Find Netezza Table Size? When you create a table in Netezza using nzsql, the table…

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May 31, 2017
Netezza

Netezza Derived Tables and Examples

In the real world scenario, you may derive the some column from base table and instead of creating temporary table you may use that derived query in FROM clause of the SQL statement. These types of queries are called derived tables. In this article,we will check on the Netezza derived tables.  Netezza Derived Tables A derived table is basically a subquery which is always in the FROM clause of a SQL query Statements. The reason it is called a derived table is because it essentially functions as a table as far as the entire query…

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May 28, 2017
Netezza

Netezza Identify and Kill Table Locks

Sometimes if you try to delete or truncate data from the table that is being used by the other process then session may lock the table resulting deadlock. You have to identify and kill such sessions before attempting to delete or truncate that table.In this article, we will discuss about Netezza identify and kill tables locks with an examples. Read: Netezza Table Locking and Concurrency Netezza Identify and Kill Table Locks The mail question is how to identify the locks? There are couple of options available to identify the table…

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May 26, 2017
BigData

Hadoop Hive Analytic Functions and Examples

Hadoop Hive analytic functions compute an aggregate value that is based on a group of rows. A Hadoop Hive HQL analytic function works on the group of rows and ignores the NULL in the data if you specify. Hadoop Hive analytic functions Latest Hive version includes many useful functions that can perform day to day aggregation. Note that, Hive is batch query processing engine and hence take more time to execute. Read: Apache Hive ROWNUM Pseudo Column Equivalent Hadoop Hive Date Functions and Examples Spark SQL Analytic Functions and Examples…

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May 25, 2017
BigData

Hadoop Hive Cumulative Sum, Average and Example

Latest version of Hive HQL supports the window analytics functions. You can make use of the Hadoop Hive Analytic functions to calculate the cumulative sum or running sum and cumulative average. Sum and Average analytical functions are used along with window options to calculate the Hadoop Hive Cumulative Sum or running sum. Hadoop Hive Cumulative Sum, Average Syntax: Below are the Syntax for Apache Hive Cumulative SUM, AVG analytic functions. You can use these function within query you have requirement to calculate cumulative SUM or AVG. SUM([DISTINCT | ALL] expression)…

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May 24, 2017
BigData

Run Hive Script File Passing Parameter and Working Example

Hive is used for batch and interactive SQL queries. Variable Substitution allows for tasks such as separating environment-specific configuration variables from code. The variable substitution is very important when you are calling the HQL scripts from shell or Python. You can pass the values to query that you are calling. In this article, we will see how to run Hive script file passing parameter to it. We also see the working examples. Run Hive Script File Passing Parameter You can use the set and use that variable within the script.…

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May 24, 2017
BigData

Hive String Functions and Examples

In this article, we will discuss on the various Hive string functions and usage. The HQL string functions are similar to the SQL string functions. Hive String Functions The string functions in Hive are listed below: Read: Apache Hive Extract Function Alternative and Examples Apache Hive group_concat Alternative and Example Hadoop Hive Regular Expression Functions and Examples Hadoop Hive Date Functions and Examples Hive concat (string A, string B,...) Function This Hive built-in strig function cocatenates all the given strings: hive> select CONCAT('concat','->','demo'); OK concat->demo Hive substr(string, int start, int…

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May 21, 2017
General

Netezza SQL Interview Questions and Explanation

Below are some of best Netezza SQL interview questions that you may face: How do you improve performance of SQL queries? There are various options that you can use to improve the performance of Netezza queries. Read below post for all SQL optimization options. Steps to Optimize SQL Query Performance – Best Practices How to calculate the Cumulative Sum in Netezza? You can make use of the Netezza analytical functions to calculate the cumulative sum or running sum. Read: Netezza Cumulative Sum, Average and Example How do you Identify and…

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May 21, 2017
BigData

Hadoop Hive Table Dynamic Partition and Examples

Partition in Hive is used for the better performance. Hive supports the single or multi column partition. You can manually add the partition to the Hive tables or Hive can dynamically partition. You can choose either methods based on your needs. In this article, we will discuss about the Hadoop Hive table dynamic partition and demonstrate using examples. Hadoop Hive Table Dynamic Partition In Hadoop Hive, data is stored as files on HDFS, whenever you partition the table in Hive, it creates sub directories within main directory using the partition…

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May 21, 2017