PreprocessTableMerge Logical Resolution Rule¶

PreprocessTableMerge is a post-hoc logical resolution rule (Rule[LogicalPlan]) to <> in a query plan into MergeIntoCommand.md[]s.

PreprocessTableMerge is installed (injected) into a SparkSession using DeltaSparkSessionExtension.md[].

== [[creating-instance]][[conf]] Creating Instance

PreprocessTableMerge takes a single SQLConf to be created.

PreprocessTableMerge is created when:

• DeltaMergeBuilder is executed

• DeltaSparkSessionExtension is requested to DeltaSparkSessionExtension.md#apply[register Delta SQL support]

== [[apply]] Executing Rule

[source, scala]¶

apply( plan: LogicalPlan): LogicalPlan

apply resolves (replaces) DeltaMergeInto.md[] logical commands (in a logical query plan) into corresponding MergeIntoCommand.md[]s.

apply is part of the Spark SQL's Rule abstraction.