javadoc

Author: ChrisHegarty

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/MergeOperator.java

@@ -16,6 +16,10 @@
 import java.util.ListIterator;
 import java.util.function.Supplier;
 
+/**
+ * A merge operator is effectively a "fan-in" operator - accepts input
+ * from several sources and provides it in a single output.
+ */
 public class MergeOperator extends SourceOperator {
 
     private final BlockFactory blockFactory;
@@ -76,7 +80,7 @@ public Page getOutput() {
 
     @Override
     public void close() {
-        // The blocks are closable by the other exchange? so we have to copy them
+        // release blocks from any subplan not fully consumed.
         if (subPlanBlocks != null) {
             while (subPlanBlocks.hasNext()) {
                 Releasables.close(subPlanBlocks.next());

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/logical/Fork.java

@@ -10,7 +10,6 @@
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.xpack.esql.core.expression.Attribute;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
@@ -19,10 +18,14 @@
 import java.util.List;
 import java.util.Objects;
 
+/**
+ * A Fork is a {@code Plan} with one child, but holds several logical subplans, e.g.
+ * {@code FORK [WHERE content:"fox" ] [WHERE content:"dog"] }
+ */
 public class Fork extends UnaryPlan {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(LogicalPlan.class, "Fork", Fork::new);
+
     private final List<LogicalPlan> subPlans;
-    private List<Attribute> lazyOutput;
 
     public Fork(Source source, LogicalPlan child, List<LogicalPlan> subPlans) {
         super(source, child);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/logical/Merge.java

@@ -19,8 +19,13 @@
 import java.util.List;
 import java.util.Objects;
 
+/**
+ * A Merge is a {@code LeafPlan}, which holds several logical subplans.
+ */
 public class Merge extends LeafPlan {
+
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(LogicalPlan.class, "Merge", Merge::new);
+
     private final List<LogicalPlan> subPlans;
 
     public Merge(Source source, List<LogicalPlan> subPlans) {