Add performance warning for MAP_FILTER

Author: abhinavmuk04

presto-main-base/src/main/java/com/facebook/presto/sql/analyzer/ExpressionAnalyzer.java

@@ -30,6 +30,7 @@
 import com.facebook.presto.common.type.MapType;
 import com.facebook.presto.common.type.RowType;
 import com.facebook.presto.common.type.Type;
+import com.facebook.presto.common.type.TypeSignature;
 import com.facebook.presto.common.type.TypeSignatureParameter;
 import com.facebook.presto.common.type.TypeUtils;
 import com.facebook.presto.common.type.TypeWithName;
@@ -154,6 +155,7 @@
 import static com.facebook.presto.common.type.VarcharType.VARCHAR;
 import static com.facebook.presto.metadata.BuiltInTypeAndFunctionNamespaceManager.JAVA_BUILTIN_NAMESPACE;
 import static com.facebook.presto.spi.StandardErrorCode.OPERATOR_NOT_FOUND;
+import static com.facebook.presto.spi.StandardWarningCode.PERFORMANCE_WARNING;
 import static com.facebook.presto.spi.StandardWarningCode.SEMANTIC_WARNING;
 import static com.facebook.presto.sql.NodeUtils.getSortItemsFromOrderBy;
 import static com.facebook.presto.sql.analyzer.Analyzer.verifyNoAggregateWindowOrGroupingFunctions;
@@ -1118,6 +1120,17 @@ else if (frame.getType() == GROUPS) {
                     }
                 }
             }
+            List<TypeSignature> arguments = functionMetadata.getArgumentTypes();
+
+            if (!argumentTypes.isEmpty() && "map".equals(arguments.get(0).getBase())) {
+                arguments.stream()
+                        .skip(1).map(arg -> arg.getBase())
+                        .filter(base -> "function".equals(base) || "lambda".equals(base))
+                        .forEach(base -> {
+                            String warningMessage = createWarningMessage(node, "Lambdas on large maps are expensive, consider using map_subset");
+                            warningCollector.add(new PrestoWarning(PERFORMANCE_WARNING, warningMessage));
+                        });
+            }
 
             if (node.isIgnoreNulls() && node.getWindow().isPresent()) {
                 if (!functionResolution.isWindowValueFunction(function)) {

presto-main-base/src/test/java/com/facebook/presto/sql/analyzer/TestAnalyzer.java

@@ -152,6 +152,35 @@ void testNoORWarning()
         assertNoWarning(analyzeWithWarnings("SELECT * FROM t1 JOIN t2 ON t1.a = t2.a \n" + "AND (t1.b = t2.b OR t1.b > t2.b)"));
     }
 
+    @Test
+    public void testMapFilterWarnings()
+    {
+        assertHasWarning(
+                analyzeWithWarnings("SELECT map_filter(x, (k, v) -> v > 1) FROM (VALUES (map(ARRAY[1,2], ARRAY[2,3]))) AS t(x)"),
+                PERFORMANCE_WARNING,
+                "Lambdas on large maps are expensive, consider using map_subset");
+
+        assertHasWarning(
+                analyzeWithWarnings("SELECT map_filter(x, (k, v) -> k = 2) FROM (VALUES (map(ARRAY[1,2,3], ARRAY[10,20,30]))) AS t(x)"),
+                PERFORMANCE_WARNING,
+                "Lambdas on large maps are expensive, consider using map_subset");
+
+        assertHasWarning(
+                analyzeWithWarnings("SELECT map_filter(x, (k, v) -> k IN (1, 3)) FROM (VALUES (map(ARRAY[1,2,3], ARRAY[10,20,30]))) AS t(x)"),
+                PERFORMANCE_WARNING,
+                "Lambdas on large maps are expensive, consider using map_subset");
+
+        assertHasWarning(
+                analyzeWithWarnings("SELECT map_filter(x, (k, v) -> v IN (20, 30)) FROM (VALUES (map(ARRAY[1,2,3], ARRAY[10,20,30]))) AS t(x)"),
+                PERFORMANCE_WARNING,
+                "Lambdas on large maps are expensive, consider using map_subset");
+
+        assertHasWarning(
+                analyzeWithWarnings("SELECT map_filter(x, (k, v) -> k + v > 25) FROM (VALUES (map(ARRAY[1,2,3], ARRAY[10,20,30]))) AS t(x)"),
+                PERFORMANCE_WARNING,
+                "Lambdas on large maps are expensive, consider using map_subset");
+    }
+
     @Test
     public void testIgnoreNullWarning()
     {