Day: March 14, 2023

Create Daily product Revenue table

Nested subqueries in Hive are used to perform complex data analysis by nesting one query inside another. A subquery is a query that is nested inside another query, and it is used to retrieve data that will be used in the main query. Hive supports nested subqueries in the WHERE, HAVING, and FROM clauses. The …

Section 12.147. Quick recap-nested-sub-queries Read More »

The order of execution in SQL is generally determined by the logical order of the clauses in the SQL statement. Here is a general order of execution for a typical SQL query: FROM clause: This clause identifies the table or tables that are the source of the data. WHERE clause: This clause filters the data …

Section 12.146.understanding-order-of-execution-of-sql Read More »

Rank, Dense Rank, and Row Number are window functions in SQL used to assign a unique number to each row within a partition, but they differ in their approach and behavior. Here is a brief explanation of the differences between these three functions: ROW_NUMBER(): This function assigns a unique sequential number to each row within …

Section.12.145. difference-between-rank-dense-rank-and-row-number Read More »

Performing aggregations using windowing functions in Hive involves using functions such as SUM(), AVG(), MIN(), MAX(), and COUNT() over a window or subset of rows. Here is an example of how to use windowing functions

Windowing functions in Hive are defined using the OVER() clause, which specifies the window or subset of rows over which the function will operate. The window can be defined using a range of methods, including ROWS BETWEEN, RANGE BETWEEN, and UNBOUNDED PRECEDING/FOLLOWING. Some of the commonly used analytics or windowing functions in Hive include: ROW_NUMBER() …

Section.12.136. Overview of Analytics or Windowing Functions Read More »