PrepareDeltaScan Logical Optimization¶

PrepareDeltaScan is a PrepareDeltaScanBase.

Creating Instance¶

PrepareDeltaScan takes the following to be created:

• SparkSession (Spark SQL)

PrepareDeltaScan is created when:

• DeltaSparkSessionExtension is requested to register delta extensions (and injects pre-CBO optimizer rules)

Logging¶

Enable ALL logging level for org.apache.spark.sql.delta.stats.PrepareDeltaScan logger to see what happens inside.

Add the following line to conf/log4j.properties:

log4j.logger.org.apache.spark.sql.delta.stats.PrepareDeltaScan=ALL

Refer to Logging.