[release-20.0] bugfix: Allow cross-keyspace joins (#16520) (#16524)

Signed-off-by: Andres Taylor <[email protected]>
Co-authored-by: vitess-bot[bot] <108069721+vitess-bot[bot]@users.noreply.github.com>

.github/workflows/vitess_tester_vtgate.yml

@@ -112,7 +112,7 @@ jobs:
         go install github.com/vitessio/go-junit-report@HEAD
         
         # install vitess tester
-        go install github.com/vitessio/vitess-tester@eb953122baba163ed8ccaa6642458ee984f5d7e4
+        go install github.com/vitessio/vitess-tester@89dd933a9ea0e15f69ca58b9c8ea09a358762cca
 
     - name: Setup launchable dependencies
       if: steps.skip-workflow.outputs.is_draft == 'false' && steps.skip-workflow.outputs.skip-workflow == 'false' && steps.changes.outputs.end_to_end == 'true' && github.base_ref == 'main'
@@ -143,9 +143,9 @@ jobs:
           # We go over all the directories in the given path.
           # If there is a vschema file there, we use it, otherwise we let vitess-tester autogenerate it.
           if [ -f $dir/vschema.json ]; then
-            vitess-tester --sharded --xunit --test-dir $dir --vschema "$dir"vschema.json
+            vitess-tester --xunit --vschema "$dir"vschema.json $dir/*.test
           else 
-            vitess-tester --sharded --xunit --test-dir $dir
+            vitess-tester --sharded --xunit $dir/*.test
           fi
           # Number the reports by changing their file names.
           mv report.xml report"$i".xml

go/test/endtoend/vtgate/vitess_tester/two_sharded_keyspaces/queries.test

@@ -0,0 +1,26 @@
+use customer;
+create table if not exists customer(
+                                       customer_id bigint not null,
+                                       email varbinary(128),
+                                       primary key(customer_id)
+) ENGINE=InnoDB;
+insert into customer.customer(customer_id, email) values(1, '[[email protected]](mailto:[email protected])');
+insert into customer.customer(customer_id, email) values(2, '[[email protected]](mailto:[email protected])');
+insert into customer.customer(customer_id, email) values(3, '[[email protected]](mailto:[email protected])');
+insert into customer.customer(customer_id, email) values(4, '[[email protected]](mailto:[email protected])');
+insert into customer.customer(customer_id, email) values(5, '[[email protected]](mailto:[email protected])');
+use corder;
+create table if not exists corder(
+                                     order_id bigint not null,
+                                     customer_id bigint,
+                                     sku varbinary(128),
+                                     price bigint,
+                                     primary key(order_id)
+) ENGINE=InnoDB;
+insert into corder.corder(order_id, customer_id, sku, price) values(1, 1, 'SKU-1001', 100);
+insert into corder.corder(order_id, customer_id, sku, price) values(2, 2, 'SKU-1002', 30);
+insert into corder.corder(order_id, customer_id, sku, price) values(3, 3, 'SKU-1002', 30);
+insert into corder.corder(order_id, customer_id, sku, price) values(4, 4, 'SKU-1002', 30);
+insert into corder.corder(order_id, customer_id, sku, price) values(5, 5, 'SKU-1002', 30);
+
+select co.order_id, co.customer_id, co.price from corder.corder co left join customer.customer cu on co.customer_id=cu.customer_id where cu.customer_id=1;

go/test/endtoend/vtgate/vitess_tester/two_sharded_keyspaces/vschema.json

@@ -0,0 +1,72 @@
+{
+  "keyspaces": {
+    "customer": {
+      "sharded": true,
+      "vindexes": {
+        "hash": {
+          "type": "hash",
+          "params": {},
+          "owner": ""
+        }
+      },
+      "tables": {
+        "customer": {
+          "type": "",
+          "column_vindexes": [
+            {
+              "column": "customer_id",
+              "name": "hash",
+              "columns": []
+            }
+          ],
+          "columns": [],
+          "pinned": "",
+          "column_list_authoritative": false,
+          "source": ""
+        }
+      },
+      "require_explicit_routing": false,
+      "foreign_key_mode": 0,
+      "multi_tenant_spec": null
+    },
+    "corder": {
+      "sharded": true,
+      "vindexes": {
+        "hash": {
+          "type": "hash",
+          "params": {},
+          "owner": ""
+        }
+      },
+      "tables": {
+        "corder": {
+          "type": "",
+          "column_vindexes": [
+            {
+              "column": "customer_id",
+              "name": "hash",
+              "columns": []
+            }
+          ],
+          "columns": [],
+          "pinned": "",
+          "column_list_authoritative": false,
+          "source": ""
+        }
+      },
+      "require_explicit_routing": false,
+      "foreign_key_mode": 0,
+      "multi_tenant_spec": null
+    }
+  },
+  "routing_rules": {
+    "rules": []
+  },
+  "shard_routing_rules": {
+    "rules": []
+  },
+  "keyspace_routing_rules": null,
+  "mirror_rules": {
+    "rules": []
+  }
+}

go/vt/vtgate/planbuilder/operators/join_merging.go

@@ -64,7 +64,7 @@ func mergeJoinInputs(ctx *plancontext.PlanningContext, lhs, rhs Operator, joinPr
 
 	// sharded routing is complex, so we handle it in a separate method
 	case a == sharded && b == sharded:
-		return tryMergeJoinShardedRouting(ctx, lhsRoute, rhsRoute, m, joinPredicates)
+		return tryMergeShardedRouting(ctx, lhsRoute, rhsRoute, m, joinPredicates, false /*isSubquery*/)
 
 	default:
 		return nil

go/vt/vtgate/planbuilder/operators/sharded_routing.go

@@ -634,11 +634,12 @@ func (tr *ShardedRouting) extraInfo() string {
 	)
 }
 
-func tryMergeJoinShardedRouting(
+func tryMergeShardedRouting(
 	ctx *plancontext.PlanningContext,
 	routeA, routeB *Route,
 	m merger,
 	joinPredicates []sqlparser.Expr,
+	isSubquery bool,
 ) *Route {
 	sameKeyspace := routeA.Routing.Keyspace() == routeB.Routing.Keyspace()
 	tblA := routeA.Routing.(*ShardedRouting)
@@ -670,7 +671,10 @@ func tryMergeJoinShardedRouting(
 		}
 
 		if !sameKeyspace {
-			panic(vterrors.VT12001("cross-shard correlated subquery"))
+			if isSubquery {
+				panic(vterrors.VT12001("cross-shard correlated subquery"))
+			}
+			return nil
 		}
 
 		canMerge := canMergeOnFilters(ctx, routeA, routeB, joinPredicates)

go/vt/vtgate/planbuilder/operators/subquery_planning.go

@@ -722,7 +722,7 @@ func mergeSubqueryInputs(ctx *plancontext.PlanningContext, in, out Operator, joi
 
 	// sharded routing is complex, so we handle it in a separate method
 	case inner == sharded && outer == sharded:
-		return tryMergeJoinShardedRouting(ctx, inRoute, outRoute, m, joinPredicates)
+		return tryMergeShardedRouting(ctx, inRoute, outRoute, m, joinPredicates, true /*isSubquery*/)
 
 	default:
 		return nil

go/vt/vtgate/planbuilder/testdata/from_cases.json

@@ -4522,6 +4522,55 @@
       ]
     }
   },
+  {
+    "comment": "Cross keyspace join",
+    "query": "select 1 from user join t1 on user.id = t1.id",
+    "plan": {
+      "QueryType": "SELECT",
+      "Original": "select 1 from user join t1 on user.id = t1.id",
+      "Instructions": {
+        "OperatorType": "Join",
+        "Variant": "Join",
+        "JoinColumnIndexes": "L:0",
+        "JoinVars": {
+          "t1_id": 1
+        },
+        "TableName": "t1_`user`",
+        "Inputs": [
+          {
+            "OperatorType": "Route",
+            "Variant": "Scatter",
+            "Keyspace": {
+              "Name": "zlookup_unique",
+              "Sharded": true
+            },
+            "FieldQuery": "select 1, t1.id from t1 where 1 != 1",
+            "Query": "select 1, t1.id from t1",
+            "Table": "t1"
+          },
+          {
+            "OperatorType": "Route",
+            "Variant": "EqualUnique",
+            "Keyspace": {
+              "Name": "user",
+              "Sharded": true
+            },
+            "FieldQuery": "select 1 from `user` where 1 != 1",
+            "Query": "select 1 from `user` where `user`.id = :t1_id",
+            "Table": "`user`",
+            "Values": [
+              ":t1_id"
+            ],
+            "Vindex": "user_index"
+          }
+        ]
+      },
+      "TablesUsed": [
+        "user.user",
+        "zlookup_unique.t1"
+      ]
+    }
+  },
   {
     "comment": "Select everything from a derived table having a cross-shard join",
     "query": "select * from (select u.foo * ue.bar from user u join user_extra ue) as dt",

go/vt/vtgate/planbuilder/testdata/unsupported_cases.json

@@ -294,6 +294,11 @@
     "query": "select 1 from music union (select id from user union all select name from unsharded)",
     "plan": "VT12001: unsupported: nesting of UNIONs on the right-hand side"
   },
+  {
+    "comment": "Cross keyspace query with subquery",
+    "query": "select 1 from user where id in (select id from t1)",
+    "plan": "VT12001: unsupported: cross-shard correlated subquery"
+  },
   {
     "comment": "multi-shard union",
     "query": "select 1 from music union (select id from user union select name from unsharded)",

test/templates/cluster_vitess_tester.tpl

@@ -110,7 +110,7 @@ jobs:
         go install github.com/vitessio/go-junit-report@HEAD
 
         # install vitess tester
-        go install github.com/vitessio/vitess-tester@eb953122baba163ed8ccaa6642458ee984f5d7e4
+        go install github.com/vitessio/vitess-tester@89dd933a9ea0e15f69ca58b9c8ea09a358762cca
 
     - name: Setup launchable dependencies
       if: steps.skip-workflow.outputs.is_draft == 'false' && steps.skip-workflow.outputs.skip-workflow == 'false' && steps.changes.outputs.end_to_end == 'true' && github.base_ref == 'main'
@@ -141,9 +141,9 @@ jobs:
           # We go over all the directories in the given path.
           # If there is a vschema file there, we use it, otherwise we let vitess-tester autogenerate it.
           if [ -f $dir/vschema.json ]; then
-            vitess-tester --sharded --xunit --test-dir $dir --vschema "$dir"vschema.json
+            vitess-tester --xunit --vschema "$dir"vschema.json $dir/*.test
           else 
-            vitess-tester --sharded --xunit --test-dir $dir
+            vitess-tester --sharded --xunit $dir/*.test
           fi
           # Number the reports by changing their file names.
           mv report.xml report"$i".xml