Package org.elasticsearch.xpack.esql.approximation

Class ForkApproximation

java.lang.Object

org.elasticsearch.xpack.esql.approximation.ForkApproximation

All Implemented Interfaces:

ApproximationDriver

public final class ForkApproximation
extends Object
implements ApproximationDriver

Approximation for a query that contains FORK and STATS in one or more branches.

The approximation process is similar to Approximation, and makes heavy use of that:

• The source count is obtained by executing the source count plan of any the branches.
• If needed, the (filtered) counts are obtained by creating a FORK query containing the branches' count subplans.

Each branch gets its individual sample probability.

Method Summary

Modifier and Type	Method	Description
LogicalPlan	firstSubPlan()	Returns the next subplan to execute for calibration, or null if the main plan can run.
LogicalPlan	newMainPlan(LogicalPlan mainPlan, Result result)	Processes a subplan result and returns the main plan with placeholders substituted when this calibration step is complete.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

firstSubPlan

public LogicalPlan firstSubPlan()

Description copied from interface: ApproximationDriver

Returns the next subplan to execute for calibration, or null if the main plan can run.

Specified by:

firstSubPlan in interface ApproximationDriver

newMainPlan

public LogicalPlan newMainPlan(LogicalPlan mainPlan,
 Result result)

Description copied from interface: ApproximationDriver

Processes a subplan result and returns the main plan with placeholders substituted when this calibration step is complete.

Specified by:

newMainPlan in interface ApproximationDriver