Remove legacy array_agg semantics

The behavior has been disabled behind a config flag for more than
three years.

presto-main/src/main/java/io/prestosql/metadata/FunctionRegistry.java

@@ -602,7 +602,7 @@ public FunctionRegistry(TypeManager typeManager, BlockEncodingSerde blockEncodin
                 .function(ARRAY_FLATTEN_FUNCTION)
                 .function(ARRAY_CONCAT_FUNCTION)
                 .functions(ARRAY_CONSTRUCTOR, ARRAY_SUBSCRIPT, ARRAY_TO_JSON, JSON_TO_ARRAY, JSON_STRING_TO_ARRAY)
-                .function(new ArrayAggregationFunction(featuresConfig.isLegacyArrayAgg(), featuresConfig.getArrayAggGroupImplementation()))
+                .function(new ArrayAggregationFunction(featuresConfig.getArrayAggGroupImplementation()))
                 .functions(new MapSubscriptOperator(featuresConfig.isLegacyMapSubscript()))
                 .functions(MAP_CONSTRUCTOR, MAP_TO_JSON, JSON_TO_MAP, JSON_STRING_TO_MAP)
                 .functions(MAP_AGG, MAP_UNION)

presto-main/src/main/java/io/prestosql/operator/aggregation/arrayagg/ArrayAggregationFunction.java

@@ -39,7 +39,6 @@
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static io.prestosql.metadata.Signature.typeVariable;
 import static io.prestosql.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INDEX;
-import static io.prestosql.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.BLOCK_INPUT_CHANNEL;
 import static io.prestosql.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.NULLABLE_BLOCK_INPUT_CHANNEL;
 import static io.prestosql.operator.aggregation.AggregationMetadata.ParameterMetadata.ParameterType.STATE;
 import static io.prestosql.operator.aggregation.AggregationUtils.generateAggregationName;
@@ -55,17 +54,15 @@ public class ArrayAggregationFunction
     private static final MethodHandle COMBINE_FUNCTION = methodHandle(ArrayAggregationFunction.class, "combine", Type.class, ArrayAggregationState.class, ArrayAggregationState.class);
     private static final MethodHandle OUTPUT_FUNCTION = methodHandle(ArrayAggregationFunction.class, "output", Type.class, ArrayAggregationState.class, BlockBuilder.class);
 
-    private final boolean legacyArrayAgg;
     private final ArrayAggGroupImplementation groupMode;
 
-    public ArrayAggregationFunction(boolean legacyArrayAgg, ArrayAggGroupImplementation groupMode)
+    public ArrayAggregationFunction(ArrayAggGroupImplementation groupMode)
     {
         super(NAME,
                 ImmutableList.of(typeVariable("T")),
                 ImmutableList.of(),
                 parseTypeSignature("array(T)"),
                 ImmutableList.of(parseTypeSignature("T")));
-        this.legacyArrayAgg = legacyArrayAgg;
         this.groupMode = requireNonNull(groupMode, "groupMode is null");
     }
 
@@ -79,10 +76,10 @@ public String getDescription()
     public InternalAggregationFunction specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry)
     {
         Type type = boundVariables.getTypeVariable("T");
-        return generateAggregation(type, legacyArrayAgg, groupMode);
+        return generateAggregation(type, groupMode);
     }
 
-    private static InternalAggregationFunction generateAggregation(Type type, boolean legacyArrayAgg, ArrayAggGroupImplementation groupMode)
+    private static InternalAggregationFunction generateAggregation(Type type, ArrayAggGroupImplementation groupMode)
     {
         DynamicClassLoader classLoader = new DynamicClassLoader(ArrayAggregationFunction.class.getClassLoader());
 
@@ -92,7 +89,7 @@ private static InternalAggregationFunction generateAggregation(Type type, boolea
         List<Type> inputTypes = ImmutableList.of(type);
         Type outputType = new ArrayType(type);
         Type intermediateType = stateSerializer.getSerializedType();
-        List<ParameterMetadata> inputParameterMetadata = createInputParameterMetadata(type, legacyArrayAgg);
+        List<ParameterMetadata> inputParameterMetadata = createInputParameterMetadata(type);
 
         MethodHandle inputFunction = INPUT_FUNCTION.bindTo(type);
         MethodHandle combineFunction = COMBINE_FUNCTION.bindTo(type);
@@ -115,9 +112,9 @@ private static InternalAggregationFunction generateAggregation(Type type, boolea
         return new InternalAggregationFunction(NAME, inputTypes, ImmutableList.of(intermediateType), outputType, true, true, factory);
     }
 
-    private static List<ParameterMetadata> createInputParameterMetadata(Type value, boolean legacyArrayAgg)
+    private static List<ParameterMetadata> createInputParameterMetadata(Type value)
     {
-        return ImmutableList.of(new ParameterMetadata(STATE), new ParameterMetadata(legacyArrayAgg ? BLOCK_INPUT_CHANNEL : NULLABLE_BLOCK_INPUT_CHANNEL, value), new ParameterMetadata(BLOCK_INDEX));
+        return ImmutableList.of(new ParameterMetadata(STATE), new ParameterMetadata(NULLABLE_BLOCK_INPUT_CHANNEL, value), new ParameterMetadata(BLOCK_INDEX));
     }
 
     public static void input(Type type, ArrayAggregationState state, Block value, int position)

presto-main/src/main/java/io/prestosql/sql/analyzer/FeaturesConfig.java

@@ -81,7 +81,6 @@ public class FeaturesConfig
     private boolean enableIntermediateAggregations;
     private boolean pushTableWriteThroughUnion = true;
     private boolean exchangeCompressionEnabled;
-    private boolean legacyArrayAgg;
     private boolean groupByUsesEqualTo;
     private boolean legacyTimestamp = true;
     private boolean legacyMapSubscript;
@@ -220,18 +219,6 @@ public boolean isLegacyCharToVarcharCoercion()
         return legacyCharToVarcharCoercion;
     }
 
-    @Config("deprecated.legacy-array-agg")
-    public FeaturesConfig setLegacyArrayAgg(boolean legacyArrayAgg)
-    {
-        this.legacyArrayAgg = legacyArrayAgg;
-        return this;
-    }
-
-    public boolean isLegacyArrayAgg()
-    {
-        return legacyArrayAgg;
-    }
-
     @Config("deprecated.group-by-uses-equal")
     public FeaturesConfig setGroupByUsesEqualTo(boolean value)
     {

presto-main/src/test/java/io/prestosql/sql/analyzer/TestFeaturesConfig.java

@@ -68,7 +68,6 @@ public void testDefaults()
                 .setOptimizeHashGeneration(true)
                 .setPushTableWriteThroughUnion(true)
                 .setDictionaryAggregation(false)
-                .setLegacyArrayAgg(false)
                 .setGroupByUsesEqualTo(false)
                 .setLegacyMapSubscript(false)
                 .setRegexLibrary(JONI)
@@ -121,7 +120,6 @@ public void testExplicitPropertyMappings()
                 .put("experimental.enable-stats-calculator", "false")
                 .put("optimizer.ignore-stats-calculator-failures", "false")
                 .put("optimizer.default-filter-factor-enabled", "true")
-                .put("deprecated.legacy-array-agg", "true")
                 .put("deprecated.group-by-uses-equal", "true")
                 .put("deprecated.legacy-map-subscript", "true")
                 .put("deprecated.legacy-row-field-ordinal-access", "true")
@@ -203,7 +201,6 @@ public void testExplicitPropertyMappings()
                 .setPushTableWriteThroughUnion(false)
                 .setDictionaryAggregation(true)
                 .setPushAggregationThroughJoin(false)
-                .setLegacyArrayAgg(true)
                 .setGroupByUsesEqualTo(true)
                 .setLegacyMapSubscript(true)
                 .setRegexLibrary(RE2J)