fix(interactive): Fix unexpected alias when fusion Expand + GetV (#3676)

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## What do these changes do?

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As titled.

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Fixes #3671

Author: BingqingLyu

interactive_engine/compiler/src/main/java/com/alibaba/graphscope/common/ir/planner/rules/ExpandGetVFusionRule.java

@@ -37,10 +37,13 @@
 // This rule try to fuse GraphLogicalExpand and GraphLogicalGetV if GraphLogicalExpand has no alias
 // (that it won't be visited individually later):
 // 1. if GraphLogicalGetV has no filters, then:
-//      GraphLogicalExpand + GraphLogicalGetV -> GraphPhysicalExpand(ExpandV)
+//      GraphLogicalExpand + GraphLogicalGetV -> GraphPhysicalExpand(ExpandV),
+// where GraphPhysicalExpand carries the alias of GraphLogicalGetV
 // 2. if GraphLogicalGetV has filters, then:
 //      GraphLogicalExpand + GraphLogicalGetV -> GraphPhysicalExpand(ExpandV)  +
-// GraphPhysicalGetV(VertexFilter)
+// GraphPhysicalGetV(VertexFilter),
+// where GraphPhysicalExpand carries the Default alias, and GraphPhysicalGetV carries the alias of
+// GraphLogicalGetV
 public abstract class ExpandGetVFusionRule<C extends RelRule.Config> extends RelRule<C>
         implements TransformationRule {
 
@@ -54,18 +57,27 @@ protected RelNode transform(GraphLogicalGetV getV, GraphLogicalExpand expand, Re
                         && getV.getOpt().equals(GraphOpt.GetV.START)
                 || expand.getOpt().equals(GraphOpt.Expand.BOTH)
                         && getV.getOpt().equals(GraphOpt.GetV.OTHER)) {
-            GraphPhysicalExpand physicalExpand =
-                    GraphPhysicalExpand.create(
-                            expand.getCluster(),
-                            expand.getHints(),
-                            input,
-                            expand,
-                            getV,
-                            GraphOpt.PhysicalExpandOpt.VERTEX,
-                            getV.getAliasName());
             if (ObjectUtils.isEmpty(getV.getFilters())) {
+                GraphPhysicalExpand physicalExpand =
+                        GraphPhysicalExpand.create(
+                                expand.getCluster(),
+                                expand.getHints(),
+                                input,
+                                expand,
+                                getV,
+                                GraphOpt.PhysicalExpandOpt.VERTEX,
+                                getV.getAliasName());
                 return physicalExpand;
             } else {
+                GraphPhysicalExpand physicalExpand =
+                        GraphPhysicalExpand.create(
+                                expand.getCluster(),
+                                expand.getHints(),
+                                input,
+                                expand,
+                                getV,
+                                GraphOpt.PhysicalExpandOpt.VERTEX,
+                                AliasInference.DEFAULT_NAME);
                 // If with filters, then create a GraphPhysicalGetV to do the filtering.
                 // We set alias of getV to null to avoid alias conflict (with expand's alias)
                 GraphPhysicalGetV physicalGetV =
@@ -74,7 +86,7 @@ protected RelNode transform(GraphLogicalGetV getV, GraphLogicalExpand expand, Re
                                 getV.getHints(),
                                 physicalExpand,
                                 getV,
-                                null,
+                                getV.getAliasName(),
                                 GraphOpt.PhysicalGetVOpt.ITSELF);
                 return physicalGetV;
             }

interactive_engine/compiler/src/main/java/com/alibaba/graphscope/common/ir/rel/graph/GraphPhysicalExpand.java

@@ -71,9 +71,31 @@ public static GraphPhysicalExpand create(
             GraphLogicalExpand fusedExpand,
             GraphLogicalGetV fusedGetV,
             GraphOpt.PhysicalExpandOpt physicalOpt,
-            String alias) {
+            String aliasName) {
+        GraphLogicalGetV newGetV = null;
+        if (fusedGetV != null) {
+            // if fused to output vertices, build a new getV if a new aliasName is given, to make
+            // sure the derived row type is correct (which is derived by getV)
+            if (fusedGetV.getAliasName().equals(aliasName)) {
+                newGetV = fusedGetV;
+            } else {
+                newGetV =
+                        GraphLogicalGetV.create(
+                                (GraphOptCluster) fusedGetV.getCluster(),
+                                fusedGetV.getHints(),
+                                input,
+                                fusedGetV.getOpt(),
+                                fusedGetV.getTableConfig(),
+                                aliasName,
+                                fusedGetV.getStartAlias());
+                if (ObjectUtils.isNotEmpty(fusedGetV.getFilters())) {
+                    // should not have filters, as it would built as a new PhysicalGetV
+                    newGetV.setFilters(fusedGetV.getFilters());
+                }
+            }
+        }
         return new GraphPhysicalExpand(
-                cluster, hints, input, fusedExpand, fusedGetV, physicalOpt, alias);
+                cluster, hints, input, fusedExpand, newGetV, physicalOpt, aliasName);
     }
 
     public GraphOpt.PhysicalExpandOpt getPhysicalOpt() {
@@ -104,7 +126,7 @@ public int getAliasId() {
     public RelDataType deriveRowType() {
         switch (physicalOpt) {
             case EDGE:
-                return fusedExpand.deriveRowType();
+                return fusedExpand.getRowType();
             case DEGREE:
                 {
                     RelDataTypeFactory typeFactory = getCluster().getTypeFactory();
@@ -117,7 +139,7 @@ public RelDataType deriveRowType() {
                 }
             case VERTEX:
             default:
-                return fusedGetV.deriveRowType();
+                return fusedGetV.getRowType();
         }
     }
 

interactive_engine/compiler/src/main/java/com/alibaba/graphscope/common/ir/rel/graph/GraphPhysicalGetV.java

@@ -30,6 +30,7 @@
 import org.apache.calcite.rel.RelWriter;
 import org.apache.calcite.rel.SingleRel;
 import org.apache.calcite.rel.hint.RelHint;
+import org.apache.calcite.rel.type.RelDataType;
 import org.apache.commons.lang3.ObjectUtils;
 
 import java.util.List;
@@ -102,6 +103,11 @@ public List<RelNode> getInputs() {
         return this.input == null ? ImmutableList.of() : ImmutableList.of(this.input);
     }
 
+    @Override
+    public RelDataType deriveRowType() {
+        return fusedGetV.getRowType();
+    }
+
     @Override
     public RelWriter explainTerms(RelWriter pw) {
         return pw.itemIf("input", input, !Objects.isNull(input))

interactive_engine/compiler/src/test/java/com/alibaba/graphscope/common/ir/plan/ExpandGetVFusionTest.java

@@ -229,10 +229,10 @@ public void expand_getv_fusion_4_test() {
         planner.setRoot(before);
         RelNode after = planner.findBestExp();
         Assert.assertEquals(
-                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[_],"
+                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[a],"
                         + " fusedFilter=[[=(_.age, 10)]], opt=[END], physicalOpt=[ITSELF])\n"
                         + "  GraphPhysicalExpand(tableConfig=[{isAll=false, tables=[knows]}],"
-                        + " alias=[a], opt=[OUT], physicalOpt=[VERTEX])\n"
+                        + " alias=[_], opt=[OUT], physicalOpt=[VERTEX])\n"
                         + "    GraphLogicalSource(tableConfig=[{isAll=false, tables=[person]}],"
                         + " alias=[_], opt=[VERTEX])",
                 after.explain().trim());
@@ -282,10 +282,10 @@ public void expand_getv_fusion_5_test() {
         planner.setRoot(before);
         RelNode after = planner.findBestExp();
         Assert.assertEquals(
-                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[_],"
+                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[a],"
                         + " fusedFilter=[[=(_.age, 10)]], opt=[END], physicalOpt=[ITSELF])\n"
                         + "  GraphPhysicalExpand(tableConfig=[{isAll=false, tables=[knows]}],"
-                        + " alias=[a], fusedFilter=[[=(_.weight, 5E-1)]], opt=[OUT],"
+                        + " alias=[_], fusedFilter=[[=(_.weight, 5E-1)]], opt=[OUT],"
                         + " physicalOpt=[VERTEX])\n"
                         + "    GraphLogicalSource(tableConfig=[{isAll=false, tables=[person]}],"
                         + " alias=[_], opt=[VERTEX])",

interactive_engine/compiler/src/test/java/com/alibaba/graphscope/common/ir/runtime/GraphRelToProtoTest.java

@@ -863,7 +863,7 @@ public void expand_degree_test() throws Exception {
         }
     }
 
-    // g.V().hasLabel("person").outE("knows").inV()
+    // g.V().hasLabel("person").outE("knows").inV().as("a")
     @Test
     public void expand_vertex_test() throws Exception {
         GraphBuilder builder = Utils.mockGraphBuilder();
@@ -879,11 +879,12 @@ public void expand_vertex_test() throws Exception {
                         .getV(
                                 new GetVConfig(
                                         GraphOpt.GetV.END,
-                                        new LabelConfig(false).addLabel("person")))
+                                        new LabelConfig(false).addLabel("person"),
+                                        "a"))
                         .build();
         Assert.assertEquals(
                 "GraphLogicalGetV(tableConfig=[{isAll=false, tables=[person]}],"
-                        + " alias=[_], opt=[END])\n"
+                        + " alias=[a], opt=[END])\n"
                         + "  GraphLogicalExpand(tableConfig=[{isAll=false, tables=[knows]}],"
                         + " alias=[_], opt=[OUT])\n"
                         + "    GraphLogicalSource(tableConfig=[{isAll=false, tables=[person]}],"
@@ -894,7 +895,7 @@ public void expand_vertex_test() throws Exception {
         planner.setRoot(before);
         RelNode after = planner.findBestExp();
         Assert.assertEquals(
-                "GraphPhysicalExpand(tableConfig=[{isAll=false, tables=[knows]}], alias=[_],"
+                "GraphPhysicalExpand(tableConfig=[{isAll=false, tables=[knows]}], alias=[a],"
                         + " opt=[OUT], physicalOpt=[VERTEX])\n"
                         + "  GraphLogicalSource(tableConfig=[{isAll=false, tables=[person]}],"
                         + " alias=[_], opt=[VERTEX])",
@@ -921,7 +922,7 @@ public void expand_vertex_test() throws Exception {
         }
     }
 
-    // g.V().hasLabel("person").outE("knows").inV().has("age",10), can be fused into
+    // g.V().hasLabel("person").outE("knows").inV().as("a").has("age",10), can be fused into
     // GraphPhysicalExpand + GraphPhysicalGetV
     @Test
     public void expand_vertex_filter_test() throws Exception {
@@ -1015,10 +1016,10 @@ public void expand_vertex_with_filters_test() throws Exception {
         planner.setRoot(before);
         RelNode after = planner.findBestExp();
         Assert.assertEquals(
-                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[_],"
+                "GraphPhysicalGetV(tableConfig=[{isAll=false, tables=[person]}], alias=[a],"
                         + " fusedFilter=[[=(_.age, 10)]], opt=[END], physicalOpt=[ITSELF])\n"
                         + "  GraphPhysicalExpand(tableConfig=[{isAll=false, tables=[knows]}],"
-                        + " alias=[a], fusedFilter=[[=(_.weight, 5E-1)]], opt=[OUT],"
+                        + " alias=[_], fusedFilter=[[=(_.weight, 5E-1)]], opt=[OUT],"
                         + " physicalOpt=[VERTEX])\n"
                         + "    GraphLogicalSource(tableConfig=[{isAll=false, tables=[person]}],"
                         + " alias=[_], opt=[VERTEX])",

interactive_engine/compiler/src/test/resources/proto/edge_expand_vertex_filter_test.json

@@ -45,8 +45,7 @@
             "id": 0
           }],
           "sampleRatio": 1.0
-        },
-        "alias": 0
+        }
       }
     },
     "metaData": [{
@@ -73,7 +72,8 @@
             }]
           }]
         }
-      }
+      },
+      "alias": -1
     }]
   }, {
     "opr": {
@@ -113,7 +113,8 @@
             }]
           },
           "sampleRatio": 1.0
-        }
+        },
+        "alias": 0
       }
     },
     "metaData": [{

interactive_engine/compiler/src/test/resources/proto/edge_expand_vertex_test.json

@@ -45,7 +45,8 @@
             "id": 0
           }],
           "sampleRatio": 1.0
-        }
+        },
+        "alias": 0
       }
     },
     "metaData": [{
@@ -72,8 +73,7 @@
             }]
           }]
         }
-      },
-      "alias": -1
+      }
     }]
   }, {
     "opr": {

interactive_engine/compiler/src/test/resources/proto/edge_expand_vertex_with_filters_test.json

@@ -74,8 +74,7 @@
             }]
           },
           "sampleRatio": 1.0
-        },
-        "alias": 0
+        }
       }
     },
     "metaData": [{
@@ -102,7 +101,8 @@
             }]
           }]
         }
-      }
+      },
+      "alias": -1
     }]
   }, {
     "opr": {
@@ -142,7 +142,8 @@
             }]
           },
           "sampleRatio": 1.0
-        }
+        },
+        "alias": 0
       }
     },
     "metaData": [{

interactive_engine/compiler/src/test/resources/proto/partitioned_edge_expand_vertex_filter_test.json

@@ -52,8 +52,7 @@
             "id": 0
           }],
           "sampleRatio": 1.0
-        },
-        "alias": 0
+        }
       }
     },
     "metaData": [{
@@ -80,7 +79,8 @@
             }]
           }]
         }
-      }
+      },
+      "alias": -1
     }]
   }, {
     "opr": {
@@ -127,7 +127,8 @@
             }]
           },
           "sampleRatio": 1.0
-        }
+        },
+        "alias": 0
       }
     },
     "metaData": [{

interactive_engine/compiler/src/test/resources/proto/partitioned_edge_expand_vertex_test.json

@@ -52,7 +52,8 @@
             "id": 0
           }],
           "sampleRatio": 1.0
-        }
+        },
+        "alias": 0
       }
     },
     "metaData": [{
@@ -79,8 +80,7 @@
             }]
           }]
         }
-      },
-      "alias": -1
+      }
     }]
   }, {
     "opr": {