org.apache.flink.table.plan.rules.logical.EnumerableToLogicalTableScan.scala Maven / Gradle / Ivy
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package org.apache.flink.table.plan.rules.logical
import org.apache.calcite.adapter.enumerable.EnumerableTableScan
import org.apache.calcite.plan.RelOptRule.{any, operand}
import org.apache.calcite.plan.{RelOptRule, RelOptRuleCall, RelOptRuleOperand}
import org.apache.calcite.rel.logical.LogicalTableScan
/**
* Rule that converts an EnumerableTableScan into a LogicalTableScan.
* We need this rule because Calcite creates an EnumerableTableScan
* when parsing a SQL query. We convert it into a LogicalTableScan
* so we can merge the optimization process with any plan that might be created
* by the Table API.
*/
class EnumerableToLogicalTableScan(
operand: RelOptRuleOperand,
description: String) extends RelOptRule(operand, description) {
override def onMatch(call: RelOptRuleCall): Unit = {
val oldRel = call.rel(0).asInstanceOf[EnumerableTableScan]
val table = oldRel.getTable
val newRel = LogicalTableScan.create(oldRel.getCluster, table)
call.transformTo(newRel)
}
}
object EnumerableToLogicalTableScan {
val INSTANCE = new EnumerableToLogicalTableScan(
operand(classOf[EnumerableTableScan], any),
"EnumerableToLogicalTableScan")
}