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

5 Essential IT Skills for Data Engineers

Data engineers need the following skills. These skills help you get nice job in any analytics company.
Data engineer skills
Photo Credit: Srini

Five Top Skills Need

Skill-1

Experience working with big data tools such as MapReduce, Pig, Spark, Kafka and NoSQL data stores such as MongoDB, Cassandra, HBase, etc.

Skill-2

Expertise in multi-structured data modeling, reporting on NoSQL & structured database technologies such as HBase and Cassandra, SQL.

Skill-3

Experience with languages such as Python, Perl, Ruby, Java, Scala, R etc.

Skill-4

Strong data & visual presentation skills and ability to explain insights using tools like tableau, D3 charts or other tools.

Skill-5

Basic knowledge and experience of statistical analysis tools such as R.

Comments

Popular posts from this blog

How to Fix datetime Import Error in Python Quickly

Explained Ideal Structure of Python Class

How to Check Kafka Available Brokers