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CreateHiveTableAsSelectCommand Logical Command

CreateHiveTableAsSelectCommand is a logical command that writes the result of executing a <> to a <> (per <>).

CreateHiveTableAsSelectCommand uses the given <> for the table name.

CreateHiveTableAsSelectCommand is <> when HiveAnalysis.md[HiveAnalysis] logical resolution rule is executed and resolves a ../CreateTable.md[CreateTable] logical operator with a child structured query and a Hive table.

When <>, CreateHiveTableAsSelectCommand runs (morphs itself into) a InsertIntoHiveTable.md[InsertIntoHiveTable] logical command.

val tableName = "create_hive_table_as_select_demo"
val q = sql(s"""CREATE TABLE IF NOT EXISTS $tableName USING hive SELECT 1L AS id""")
scala> q.explain(extended = true)
== Parsed Logical Plan ==
'CreateTable `create_hive_table_as_select_demo`, Ignore
+- Project [1 AS id#74L]
   +- OneRowRelation

== Analyzed Logical Plan ==
CreateHiveTableAsSelectCommand [Database:default, TableName: create_hive_table_as_select_demo, InsertIntoHiveTable]
+- Project [1 AS id#74L]
   +- OneRowRelation

== Optimized Logical Plan ==
CreateHiveTableAsSelectCommand [Database:default, TableName: create_hive_table_as_select_demo, InsertIntoHiveTable]
+- Project [1 AS id#74L]
   +- OneRowRelation

== Physical Plan ==
Execute CreateHiveTableAsSelectCommand CreateHiveTableAsSelectCommand [Database:default, TableName: create_hive_table_as_select_demo, InsertIntoHiveTable]
+- *(1) Project [1 AS id#74L]
   +- Scan OneRowRelation[]

scala> spark.table(tableName).show
+---+
| id|
+---+
|  1|
+---+

Creating Instance

CreateHiveTableAsSelectCommand takes the following to be created:

=== [[run]] Executing Data-Writing Logical Command -- run Method

[source, scala]

run( sparkSession: SparkSession, child: SparkPlan): Seq[Row]

NOTE: run is part of ../DataWritingCommand.md#run[DataWritingCommand] contract.

In summary, run runs a InsertIntoHiveTable.md[InsertIntoHiveTable] logical command.

run requests the input ../SparkSession.md[SparkSession] for ../SparkSession.md#sessionState[SessionState] that is then requested for the ../SessionState.md#catalog[SessionCatalog].

run requests the SessionCatalog to ../SessionCatalog.md#tableExists[check out whether the table exists or not].

With the Hive table available, run validates the <> and runs a InsertIntoHiveTable.md[InsertIntoHiveTable] logical command (with overwrite and ifPartitionNotExists flags disabled).

When the Hive table is not available, run asserts that the schema (of the <>) is not defined and requests the SessionCatalog to ../SessionCatalog.md#createTable[create the table] (with the ignoreIfExists flag disabled). In the end, run runs a InsertIntoHiveTable.md[InsertIntoHiveTable] logical command (with overwrite flag enabled and ifPartitionNotExists flag disabled).