Apache Spark / Dataframe API vs. SQL
Working with data using Apache Spark is possible in several ways. If you come more from a software development background, you will likely lean towards using the Dataframe API
Apache Spark / CSV file
Apache Spark, as one of the main representatives of distributed computing systems, supports several formats for reading and writing. Probably the simplest of these is the delimited text format
PL/SQL by Example / Inheritance and Polymorphism
A key concept of object-oriented programming (OOP) is inheritance, which allows grouping properties and behaviors into a hierarchy. This way, new objects can automatically acquire functionality (methods, variables, constants, etc.) from their ancestor.
PL/SQL by Example / Object
Object-oriented programming is not exclusive to higher-level languages; a very similar principle can be achieved in PL/SQL using the special OBJECT type. A class, or rather an object, is defined similarly to a package, i.e., with a specification and a body.
PL/SQL by Example / Savepoints
Savepoints are a mechanism within a PL/SQL block that allows you to divide the transaction being executed into partial units, or milestones. You can then easily return to these milestones without losing the entire transaction.
Oracle 12c / Top N rows, pagination
In older versions, limiting sorted data by the number of rows had to be implemented using a nested query. This first sorted the table, and only then was it possible to filter by count.
Oracle 12c / User-defined function in the WITH clause
The option to define a PL/SQL function or procedure inside an SQL query might seem strange at first glance, but it has one significant advantage – the database does not need to switch context, which in certain cases leads to a massive increase in performance.
Oracle 12c / Querying from an associative array
To use an array in SQL queries, it was previously necessary to create a “stored” type on the SQL server side and assign the appropriate rights… Read more
PL/SQL by Example / Exceptions
As already indicated in the introduction, the part of the block introduced by the keyword EXCEPTION is used for catching program runtime errors.