Adaptive Query Execution features include dynamically coalescing shuffle partitions, dynamically injecting scan filters, and dynamically optimizing skew joins.
This is almost correct. All of these features, except for dynamically injecting scan filters, are part of Adaptive Query Execution. Dynamically injecting scan filters for join operations to limit the amount
of data to be considered in a query is part of Dynamic Partition Pruning and not of Adaptive Query Execution.
Adaptive Query Execution reoptimizes queries at execution points.
No, Adaptive Query Execution reoptimizes queries at materialization points.
Adaptive Query Execution is enabled in Spark by default.
No, Adaptive Query Execution is disabled in Spark needs to be enabled through the spark.sql.adaptive.enabled property.
Adaptive Query Execution applies to all kinds of queries.
No, Adaptive Query Execution applies only to queries that are not streaming queries and that contain at least one exchange (typically expressed through a join, aggregate, or window operator) or
one subquery.
More info: How to Speed up SQL Queries with Adaptive Query Execution, Learning Spark, 2nd Edition, Chapter 12 (https://bit.ly/3tOh8M1)
