PlanNode¶

PlanNode is an abstraction of nodes of a query plan.

Contract¶

Building SchemaKStream¶

SchemaKStream<?> buildStream(
  PlanBuildContext buildContext)

Builds a SchemaKStream

Used when:

• ExecutionPlanBuilder is requested for a PhysicalPlan
• others (less important?)

Number of Partitions¶

int getPartitions(
  KafkaTopicClient kafkaTopicClient)

LogicalSchema¶

LogicalSchema getSchema()

Source PlanNodes¶

List<PlanNode> getSources()

Source PlanNodes:

• No sources for DataSourceNode
• The single source of SingleSourcePlanNode
• The left and right join sources of JoinNode

Used when:

• PullPhysicalPlanBuilder is requested to buildPullPhysicalPlan
• PushPhysicalPlanBuilder is requested to buildPushPhysicalPlan
• JoinNode is requested to findUpstreamJoin, getPreJoinProjectDataSources
• PlanNode is requested to getSourceNodes, resolveSelectStar, validateColumns, validateKeyPresent

Implementations¶

• DataSourceNode
• JoinNode
• SingleSourcePlanNode

Creating Instance¶

PlanNode takes the following to be created:

• PlanNodeId
• DataSourceType
• Source Name

DataSourceType¶

PlanNode is given a DataSourceType when created.

getSourceNodes¶

Stream<DataSourceNode> getSourceNodes()

For this PlanNode as DataSourceNode, getSourceNodes simply returns this DataSourceNode.

Otherwise, getSourceNodes takes the source PlanNodes and then their DataSourceNodes.

getSourceNodes is used when:

• EngineExecutor is requested to getSourceNames
• LogicalPlanner is requested to joinOnNonKeyAttribute
• JoinNode is requested to getDefaultSourceKeyFormat
• PlanNode is requested to getLeftmostSourceNode
• a few others