Create a user defined function is one of the important features of Amazon Redshift cloud data warehouse. Amazon Redshift supports creating user defined functions. You can create custom user-defined functions (UDF) using either SQL SELECT statements or Python program. In this article, we will check Redshift user defined functions examples and how to create them. Redshift User Defined Functions User defined function (UDF) in Redshift provide a powerful way to perform complex data processing tasks within the Redshift database. They can provide more control and flexibility over data processing workflows, and…

Amazon Redshift, is a fast, fully managed, petabyte-scale data warehousing service. Redshift supports various columnar compression encoding techniques. In this article we will check Redshift column compression types - Compression Encoding techniques for Redshift performance optimization. Amazon Redshift supports data compression for reducing the amount of disk storage used by a table. Amazon Redshift compression encoding can significantly reduce the storage required for a table and improve query performance by reducing I/O operations. The column compression in Redshift also helps storage optimization. Redshift Column Compression Types – Compression Encoding Columnar…

SQL Join is a clause that is used for combining specific fields from two or more tables based on the common columns available. Joins are used to combine rows from multiple tables. In this article, we will learn about different Redshift join types with some examples. Below are the tables that we will be using to demonstrate different Join types available in Redshift: Students: Id   name   city 1    AAA    London 2    BBB    Mumbai 3    CCC    Bangalore 4    DDD    Mumbai 5    EEE     Bangalore Dept: Did  name    sid 100  CS       1 101 …

Amazon Redshift supports various built in functions, you can use them to extract the numbers, alphanumeric or specific patters from strings. In this article, we will discuss about Redshift extract numbers using regular expressions and examples. In data warehouse environment, you may have different types data files extracted from different data sources. Data might be corrupted or may have unwanted characters, you can clean such a data using Redshift regular expressions. You can read about regular expression in my other post: Redshift Regular Expression Functions and Examples Redshift Extract Numbers…

Like many other relational database or data warehouse appliances, Redshift supports NVL and NVL2 functions. These functions are mainly used to handle the null values in Redshift tables. Redshift NVL Function An NVL expression returns the value of the first expression in the list that is not null. The NVL function replaces a NULL value with a replacement string that you provide in the function as argument. This function returns the first argument if it is not null, otherwise the second argument. The Redshift NVL function is equivalent to the…

Amazon Redshift uses the Massively parallel processing technique, Redshift automatically distributes data and query load across all nodes available in the cluster. In this article, we will check how Redshift distributes table data and importance of right distribution key. How Redshift distributes Table Data? Amazon Redshift uses the three types of distribution; EVEN, KEY and ALL. When you create tables you will have to tell the system which distribution it should use. You may read about distribution types and best practices: Amazon Redshift Distribution Types and Examples If you specify…