Posts

Showing posts with the label workflow

Featured Post

SQL Query: 3 Methods for Calculating Cumulative SUM

Image
SQL provides various constructs for calculating cumulative sums, offering flexibility and efficiency in data analysis. In this article, we explore three distinct SQL queries that facilitate the computation of cumulative sums. Each query leverages different SQL constructs to achieve the desired outcome, catering to diverse analytical needs and preferences. Using Window Functions (e.g., PostgreSQL, SQL Server, Oracle) SELECT id, value, SUM(value) OVER (ORDER BY id) AS cumulative_sum  FROM your_table; This query uses the SUM() window function with the OVER clause to calculate the cumulative sum of the value column ordered by the id column. Using Subqueries (e.g., MySQL, SQLite): SELECT t1.id, t1.value, SUM(t2.value) AS cumulative_sum FROM your_table t1 JOIN your_table t2 ON t1.id >= t2.id GROUP BY t1.id, t1.value ORDER BY t1.id; This query uses a self-join to calculate the cumulative sum. It joins the table with itself, matching rows where the id in the first table is greater than or

Oozie - Concepts And Architecture

Image
Oozie is a workflow/coordination system that you can use to manage Apache Hadoop jobs. It is one of the main components of Oozie is the Oozie server — a web application that runs in a Java servlet container (the standard Oozie distribution is using Tomcat). Oozie is a workflow management-server that works on the Oozie server. Role of Oozie in Workflow Management in Hadoop Jobs This server supports reading and executing Workflows, Coordinators, Bundles, and SLA definitions . It implements a set of remote Web Services APIs that can be invoked from Oozie client components and third-party applications. Add a note where the execution of the server leverages a customizable database. This database contains Workflow, Coordinator, Bundle, and SLA definitions, as well as execution states and process variables. The list of currently supported databases includes MySQL, Oracle, and Apache Derby. The Oozie shared library component is located in the Oozie HOME directory and contains code u