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UnresolvedOrdinal

UnresolvedOrdinal is a leaf expression that represents a single integer literal in Sort logical operators (in SortOrder ordering expressions) and in Aggregate logical operators (in grouping expressions) in a logical plan.

UnresolvedOrdinal is <> when SubstituteUnresolvedOrdinals logical resolution rule is executed.

// Note "order by 1" clause
val sqlText = "select id from VALUES 1, 2, 3 t1(id) order by 1"
val logicalPlan = spark.sql(sqlText).queryExecution.logical
scala> println(logicalPlan.numberedTreeString)
00 'Sort [1 ASC NULLS FIRST], true
01 +- 'Project ['id]
02    +- 'SubqueryAlias t1
03       +- 'UnresolvedInlineTable [id], [List(1), List(2), List(3)]

import org.apache.spark.sql.catalyst.analysis.SubstituteUnresolvedOrdinals
val rule = new SubstituteUnresolvedOrdinals(spark.sessionState.conf)

val logicalPlanWithUnresolvedOrdinals = rule.apply(logicalPlan)
scala> println(logicalPlanWithUnresolvedOrdinals.numberedTreeString)
00 'Sort [unresolvedordinal(1) ASC NULLS FIRST], true
01 +- 'Project ['id]
02    +- 'SubqueryAlias t1
03       +- 'UnresolvedInlineTable [id], [List(1), List(2), List(3)]

import org.apache.spark.sql.catalyst.plans.logical.Sort
val sortOp = logicalPlanWithUnresolvedOrdinals.collect { case s: Sort => s }.head
val sortOrder = sortOp.order.head

import org.apache.spark.sql.catalyst.analysis.UnresolvedOrdinal
val unresolvedOrdinalExpr = sortOrder.child.asInstanceOf[UnresolvedOrdinal]
scala> println(unresolvedOrdinalExpr)
unresolvedordinal(1)

[[creating-instance]] [[ordinal]] UnresolvedOrdinal takes a single ordinal integer when created.

UnresolvedOrdinal is an unevaluable expression.

[[resolved]] UnresolvedOrdinal can never be <> (and is replaced at <>).

[[analysis-phase]] NOTE: UnresolvedOrdinal is resolved when ResolveOrdinalInOrderByAndGroupBy logical resolution rule is executed.

NOTE: UnresolvedOrdinal in GROUP BY ordinal position is not allowed for a select list with a star (*).

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