SchemaRelationProvider — Relation Providers With Mandatory User-Defined Schema¶
SchemaRelationProvider is the <
The requirement of specifying a user-defined schema is enforced when DataSource is requested for a BaseRelation for a given data source format. If not specified, DataSource throws a AnalysisException:
A schema needs to be specified when using [className].
[[contract]] [source, scala]
package org.apache.spark.sql.sources
trait SchemaRelationProvider { def createRelation( sqlContext: SQLContext, parameters: Map[String, String], schema: StructType): BaseRelation }
.SchemaRelationProvider Contract [cols="1,2",options="header",width="100%"] |=== | Method | Description
| createRelation | [[createRelation]] Creates a BaseRelation for the user-defined schema
Used exclusively when DataSource is requested for a BaseRelation for a given data source format |===
Implementations¶
Note
No known native Spark SQL implementations.
Tip
RelationProvider is used for data source providers with schema inference.
Tip
Use both SchemaRelationProvider and RelationProvider if a data source should support both schema inference and user-defined schemas.