1. Views and Temp views
In this video, we will explore views and temp views in Databricks, focusing on their persistence, lifecycle, and role in data management. Knowing when and how to use each is key to optimizing performance and accessibility in your data workflows.
2. First look at views
First up is views!
A view is like a reusable recipe for a complex dish. It saves a query that can be reused as if it were a table. Views are persistent, meaning they stay available in the database across sessions until explicitly deleted. This makes them ideal for accessing the same query logic repeatedly.
3. View syntax
Using `CREATE VIEW` or `CREATE OR REPLACE VIEW` statements allows you to create or update views, ensuring consistent results whenever accessed. Like a recipe, views promote consistency and save time across analyses, making them ideal for dashboards, reports, or common queries.
In this example, we create a view called QuickRecipes that filters recipes with a preparation time of 30 minutes or less from the recipes table. It selects specific columns, making it easy to quickly access and reuse fast-preparation recipes.
4. Temp views
Temp views, by contrast, are more like sketches on a chalkboard — they only last as long as you're using them in the room.
These temporary objects exist solely for the current session and are automatically erased once it ends. Temp views are perfect for quick, ad-hoc analysis or intermediate data transformations that you don't need to save permanently. You can create them with `CREATE OR REPLACE TEMP VIEW`, statement making them lightweight and efficient for temporary tasks. For example, temp views are useful for staging data or doing exploratory analysis, disappearing automatically to avoid clutter.
5. Benefits of views
Both views and temp views serve distinct needs. Persistent views are great for data you need to access repeatedly, like a reusable chart or common report. If you work with regularly updated datasets and need consistent logic, views save time and ensure consistency. All users accessing a view see the same data logic, simplifying collaboration.
6. Benefits of temp views
Temp views, however, shine for quick tasks without long-term storage. Think of them as flexible tools for intermediate steps - like staging or transforming data - without creating permanent objects. Since they disappear at the end of a session, temp views help maintain a clean database and reduce overhead.
7. Summary
To summarize, views are reusable recipes for persistent and consistent outputs, while temp views are like chalkboard sketches for single-session tasks. By using these options effectively, you can streamline workflows, enhance collaboration, and optimize performance in Databricks.
8. Let's practice!
Now it's time to do some exercises. Good luck!