cloud-fan commented on a change in pull request #26231: [SPARK-29572][SQL] add
v1 read fallback API in DS v2
URL: https://github.com/apache/spark/pull/26231#discussion_r365645744
##########
File path:
sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/DataSourceV2Strategy.scala
##########
@@ -19,38 +19,75 @@ package org.apache.spark.sql.execution.datasources.v2
import scala.collection.JavaConverters._
-import org.apache.spark.sql.{AnalysisException, Strategy}
-import org.apache.spark.sql.catalyst.expressions.{And, PredicateHelper,
SubqueryExpression}
+import org.apache.spark.sql.{AnalysisException, SparkSession, Strategy}
+import org.apache.spark.sql.catalyst.expressions.{And, Expression,
NamedExpression, PredicateHelper, SubqueryExpression}
import org.apache.spark.sql.catalyst.planning.PhysicalOperation
import
org.apache.spark.sql.catalyst.plans.logical.{AlterNamespaceSetProperties,
AlterTable, AppendData, CreateNamespace, CreateTableAsSelect, CreateV2Table,
DeleteFromTable, DescribeNamespace, DescribeTable, DropNamespace, DropTable,
LogicalPlan, OverwriteByExpression, OverwritePartitionsDynamic, RefreshTable,
RenameTable, Repartition, ReplaceTable, ReplaceTableAsSelect,
SetCatalogAndNamespace, ShowCurrentNamespace, ShowNamespaces,
ShowTableProperties, ShowTables}
import org.apache.spark.sql.connector.catalog.{StagingTableCatalog,
TableCapability}
+import org.apache.spark.sql.connector.read.V1Scan
import org.apache.spark.sql.connector.read.streaming.{ContinuousStream,
MicroBatchStream}
-import org.apache.spark.sql.execution.{FilterExec, ProjectExec, SparkPlan}
+import org.apache.spark.sql.execution.{FilterExec, LeafExecNode, ProjectExec,
RowDataSourceScanExec, SparkPlan}
import org.apache.spark.sql.execution.datasources.DataSourceStrategy
import
org.apache.spark.sql.execution.streaming.continuous.{ContinuousCoalesceExec,
WriteToContinuousDataSource, WriteToContinuousDataSourceExec}
+import org.apache.spark.sql.sources.TableScan
import org.apache.spark.sql.util.CaseInsensitiveStringMap
-object DataSourceV2Strategy extends Strategy with PredicateHelper {
+class DataSourceV2Strategy(session: SparkSession) extends Strategy with
PredicateHelper {
import DataSourceV2Implicits._
+ private def withProjectAndFilter(
+ project: Seq[NamedExpression],
+ filters: Seq[Expression],
+ scan: LeafExecNode,
+ needsUnsafeConversion: Boolean): SparkPlan = {
+ val filterCondition = filters.reduceLeftOption(And)
+ val withFilter = filterCondition.map(FilterExec(_, scan)).getOrElse(scan)
+
+ if (withFilter.output != project || needsUnsafeConversion) {
+ ProjectExec(project, withFilter)
+ } else {
+ withFilter
+ }
+ }
+
override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
+ case PhysicalOperation(project, filters,
+ relation @ DataSourceV2ScanRelation(_, v1Scan: V1Scan, output)) =>
+ val pushedFilters =
relation.getTagValue(V2ScanRelationPushDown.PUSHED_FILTERS_TAG)
+ .getOrElse(Seq.empty)
+ val v1Relation = v1Scan.toV1TableScan(session.sqlContext)
+ if (v1Relation.schema != v1Scan.readSchema()) {
+ throw new IllegalArgumentException(
+ "The fallback v1 relation reports inconsistent schema:\n" +
+ "Schema of v2 scan: " + v1Scan.readSchema() + "\n" +
+ "Schema of v1 relation: " + v1Relation.schema)
+ }
+ val rdd = v1Relation match {
+ case s: TableScan => s.buildScan()
+ case _ =>
+ throw new IllegalArgumentException(
+ "`V1Scan.toV1Relation` must return a `TableScan` instance.")
+ }
+ val unsafeRowRDD = DataSourceStrategy.toCatalystRDD(v1Relation, output,
rdd)
+ val originalOutputNames = relation.table.schema().map(_.name)
+ val requiredColumnsIndex =
output.map(_.name).map(originalOutputNames.indexOf)
+ val dsScan = RowDataSourceScanExec(
Review comment:
The Scala auxiliary constructors must call other constructors as the FIRST
action, e.g.
```
def this(...) {
do something
this(...)
}
```
is not allowed.
We can create an object and add an `apply` method to encapsulate the 4 lines
of code, but does it really matter? The 4 lines of code only appear once here.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
