Answer: ANSI

The question asks for the default SQL dialect used in Databricks SQL. According to Databricks documentation and the community discussion consensus (100% agreement on option C), Databricks SQL uses ANSI SQL as its default dialect. Option A (Databricks SQL) refers to the product name itself, not the dialect standard. Option B (Spark SQL) is the underlying engine but not the default dialect. Option D (Delta SQL) is not a standard SQL dialect but refers to operations specific to Delta Lake tables. Therefore, ANSI is the correct answer as it represents the standard SQL compliance that Databricks SQL defaults to.

Author: LeetQuiz Editorial Team