Warning indeterminable

Author: jan-elastic

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

@@ -19,16 +19,17 @@
 import org.elasticsearch.xpack.ml.aggs.changepoint.ChangeType;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class ChangePointOperator implements Operator {
 
     // TODO: close upon failure / interrupt
 
-    public record Factory(int inputChannel) implements OperatorFactory {
+    public record Factory(int inputChannel, String sourceText, int sourceLine, int sourceColumn) implements OperatorFactory {
         @Override
         public Operator get(DriverContext driverContext) {
-            return new ChangePointOperator(driverContext.blockFactory(), inputChannel);
+            return new ChangePointOperator(driverContext, inputChannel, sourceText, sourceLine, sourceColumn);
         }
 
         @Override
@@ -37,17 +38,23 @@ public String describe() {
         }
     }
 
-    private final BlockFactory blockFactory;
+    private final DriverContext driverContext;
     private final int inputChannel;
+    private final String sourceText;
+    private final int sourceLine;
+    private final int sourceColumn;
+
     private final List<Page> inputPages;
     private final List<Page> outputPages;
-
     private boolean finished;
     private int outputPageIndex;
 
-    public ChangePointOperator(BlockFactory blockFactory, int inputChannel) {
-        this.blockFactory = blockFactory;
+    public ChangePointOperator(DriverContext driverContext, int inputChannel, String sourceText, int sourceLine, int sourceColumn) {
+        this.driverContext = driverContext;
         this.inputChannel = inputChannel;
+        this.sourceText = sourceText;
+        this.sourceLine = sourceLine;
+        this.sourceColumn = sourceColumn;
 
         finished = false;
         inputPages = new ArrayList<>();
@@ -109,8 +116,13 @@ private void createOutputPages() {
         ChangeType changeType = ChangePointDetector.getChangeType(new MlAggsHelper.DoubleBucketValues(null, values));
         int changePointIndex = changeType.changePoint();
 
-        // TODO: throw error when indeterminable, due to not enough data
+        if (changeType instanceof ChangeType.Indeterminable indeterminable) {
+            Warnings.createWarnings(driverContext.warningsMode(), sourceLine, sourceColumn, sourceText)
+                .registerException(new IllegalArgumentException(indeterminable.getReason()));
+        }
 
+        // TODO: throw error when indeterminable, due to not enough data
+        BlockFactory blockFactory = driverContext.blockFactory();
         int pageStartIndex = 0;
         for (Page inputPage : inputPages) {
             Block changeTypeBlock;

x-pack/plugin/esql/qa/testFixtures/src/main/resources/change_point.csv-spec

@@ -206,3 +206,21 @@ null            | null
 null            | null
 null            | null
 ;
+
+
+not enough data
+// TODO: required_capability: change_point
+
+FROM k8s
+  | STATS count=COUNT() BY @timestamp=BUCKET(@timestamp, 10 MINUTES)
+  | CHANGE_POINT count ON @timestamp AS type, pvalue
+;
+
+warning:Line 3:3: evaluation of [CHANGE_POINT count ON @timestamp AS type, pvalue] failed, treating result as null. Only first 20 failures recorded.
+warning:Line 3:3: java.lang.IllegalArgumentException: not enough buckets to calculate change_point. Requires at least [22]; found [3]
+
+count:long | @timestamp:datetime      | type:text | pvalue:double
+84         | 2024-05-10T00:00:00.000Z | null      | null         
+93         | 2024-05-10T00:10:00.000Z | null      | null         
+23         | 2024-05-10T00:20:00.000Z | null      | null     
+;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/planner/LocalExecutionPlanner.java

@@ -705,7 +705,7 @@ private PhysicalOperation planMvExpand(MvExpandExec mvExpandExec, LocalExecution
     private PhysicalOperation planChangePoint(ChangePointExec changePoint, LocalExecutionPlannerContext context) {
         PhysicalOperation source = plan(changePoint.child(), context);
         Layout layout = source.layout.builder().append(changePoint.targetType()).append(changePoint.targetPvalue()).build();
-        return source.with(new ChangePointOperator.Factory(layout.get(changePoint.value().id()).channel()), layout);
+        return source.with(new ChangePointOperator.Factory(layout.get(changePoint.value().id()).channel(), changePoint.sourceText(), changePoint.sourceLocation().getLineNumber(), changePoint.sourceLocation().getColumnNumber()), layout);
     }
 
     /**

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/changepoint/ChangeType.java

@@ -121,6 +121,10 @@ public String getName() {
             return NAME;
         }
 
+        public String getReason() {
+            return reason;
+        }
+
         @Override
         public boolean equals(Object o) {
             if (this == o) return true;