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ShowDeltaTableColumnsCommand Unary Logical Operator

ShowDeltaTableColumnsCommand is a DeltaCommand that represents a ShowColumns (Spark SQL) logical command in an analyzed logical query plan after DeltaAnalysis.

  (FROM | IN) [table]
  ((FROM | IN) [namespace])?

ShowDeltaTableColumnsCommand is a RunnableCommand (Spark SQL).

ShowColumnsCommand in Spark SQL

ShowDeltaTableColumnsCommand is a Delta Lake-specific variant of ShowColumnsCommand from Spark SQL.

Creating Instance

ShowDeltaTableColumnsCommand takes the following to be created:

ShowDeltaTableColumnsCommand is created when:

Child Logical Operator with Delta Table

ShowDeltaTableColumnsCommand is given a ResolvedTable (Spark SQL) with a DeltaTableV2 when created.

Executing Command

  sparkSession: SparkSession): Seq[Row]

run is part of the RunnableCommand (Spark SQL) abstraction.

run requests the DeltaLog (of the delta table) to update.

run returns the field names of the schema of the delta table.