What does the term "schema evolution" in Delta Lake refer to?

Schema evolution in Delta Lake refers to the capability to modify the structure of data tables over time in a flexible manner. This means that as your data requirements change, you can adapt the schema of your Delta tables to accommodate new fields, data types, or changes in the data model without requiring complex migration processes or downtime.

For instance, if you initially have a table with certain columns and later decide to add a new column or change the type of an existing column, Delta Lake allows you to perform these changes seamlessly. This is particularly important in environments where data is continuously being ingested and analyzed, as it ensures that the schema can adapt to reflect new insights and business needs effectively.

In contrast, adjusting the processing power of clusters relates to resource management for performance, changing data formats pertains to how data is stored, and limiting access to users deals with data security and governance, none of which address the structural adaptability of schema evolution in Delta Lake.