UnresolvedRelation Logical Operator¶

UnresolvedRelation is a leaf logical operator with a name (as a NamedRelation) that represents a named relation that has yet to be looked up in a catalog at analysis.

UnresolvedRelation is never resolved and has to be replaced using ResolveRelations logical resolution rule.

Creating Instance¶

UnresolvedRelation takes the following to be created:

Multi-part identifier
Options
isStreaming flag (default:false)

UnresolvedRelation is created (possibly indirectly using apply factory) when:

AstBuilder is requested to parse TABLE statement and table name, and create an UnresolvedRelation
DataFrameReader.table operator is used
DataFrameWriterV2 operators are used:
DataStreamReader.table (Spark Structured Streaming) operator is used
table (Catalyst DSL) operator is used

Creating UnresolvedRelation¶

apply(
  tableIdentifier: TableIdentifier): UnresolvedRelation
apply(
  tableIdentifier: TableIdentifier,
  extraOptions: CaseInsensitiveStringMap,
  isStreaming: Boolean): UnresolvedRelation

apply creates an UnresolvedRelation.

apply is used when:

DataFrameWriter.insertInto operator is used
SparkSession.table operator is used

Name¶

Signature

name: String

name is part of the NamedRelation abstraction.

name is quoted multi-part dot-separated table name.

Quoted Multi-Part Dot-Separated Table Name¶

tableName: String

tableName is a quoted multi-part .-separated multipartIdentifier.

resolved¶

Signature

resolved: Boolean

resolved is part of the LogicalPlan abstraction.

resolved is disabled (false).

nodePatterns¶

Signature

nodePatterns: Seq[TreePattern]

nodePatterns is part of the TreeNode abstraction.

nodePatterns is a single-element collection with UNRESOLVED_RELATION.