by lochan2014 | Aug 2, 2024 | SQL
Let’s list all possible places where subqueries in MySQL or Hive QL or Pyspark SQL Query can be used: 1. In the SELECT Clause Subqueries can compute a value for each row. SELECT employee_id, (SELECT COUNT(*) FROM project_assignments pa WHERE pa.employee_id =... by lochan2014 | Jun 6, 2024 | SQL
Common Table Expressions (CTEs) are a useful feature in SQL for simplifying complex queries and improving readability. Both Oracle PL/SQL and Apache Hive support CTEs, although there may be slight differences in their syntax and usage. Common Table Expressions in... by lochan2014 | Jun 26, 2024 | SQL
Temporary functions allow users to define functions that are session-specific and used to encapsulate reusable logic within a database session. While both PL/SQL and Spark SQL support the concept of user-defined functions, their implementation and usage differ... by lochan2014 | Jun 6, 2024 | SQL
Window functions, also known as analytic functions, perform calculations across a set of table rows that are somehow related to the current row. This is different from regular aggregate functions, which aggregate results for the entire set of rows. Both Oracle PL/SQL... by lochan2014 | Nov 25, 2024 | SQL
For Better understanding on Spark SQL windows Function and Best Usecases do refer our post Window functions in Oracle Pl/Sql and Hive explained and compared with examples. Window functions in Spark SQL are powerful tools that allow you to perform calculations across a... by lochan2014 | Jun 26, 2024 | SQL
Spark SQL supports several types of joins, each suited to different use cases. Below is a detailed explanation of each join type, including syntax examples and comparisons. Types of Joins in Spark SQL Inner Join Left (Outer) Join Right (Outer) Join Full (Outer) Join...