Added foreign_key_checks to ignored set

Signed-off-by: Saif Alharthi <saif@saifalharthi.me>

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/golang/mock v1.3.1
 	github.com/golang/protobuf v1.3.2
 	github.com/golang/snappy v0.0.0-20170215233205-553a64147049
+	github.com/google/btree v1.0.0 // indirect
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf // indirect
 	github.com/gorilla/websocket v0.0.0-20160912153041-2d1e4548da23
 	github.com/grpc-ecosystem/go-grpc-middleware v1.1.0
@@ -48,6 +49,8 @@ require (
 	github.com/minio/minio-go v0.0.0-20190131015406-c8a261de75c1
 	github.com/mitchellh/go-testing-interface v1.0.0 // indirect
 	github.com/mitchellh/mapstructure v1.1.2 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.1 // indirect
 	github.com/olekukonko/tablewriter v0.0.0-20160115111002-cca8bbc07984
 	github.com/opentracing-contrib/go-grpc v0.0.0-20180928155321-4b5a12d3ff02
 	github.com/opentracing/opentracing-go v1.1.0

go/vt/vtgate/executor.go

@@ -628,7 +628,7 @@ func (e *Executor) handleSet(ctx context.Context, safeSession *SafeSession, sql
 			if !ok {
 				return nil, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unexpected value type for wait_timeout: %T", v)
 			}
-		case "sql_mode", "net_write_timeout", "net_read_timeout", "lc_messages", "collation_connection":
+		case "sql_mode", "net_write_timeout", "net_read_timeout", "lc_messages", "collation_connection", "foreign_key_checks":
 			log.Warningf("Ignored inapplicable SET %v = %v", k, v)
 			warnings.Add("IgnoredSet", 1)
 		case "charset", "names":

go/vt/vtgate/executor_test.go

@@ -437,6 +437,9 @@ func TestExecutorSet(t *testing.T) {
 	}, {
 		in:  "set net_read_timeout = 600",
 		out: &vtgatepb.Session{Autocommit: true},
+	}, {
+		in:  "set foreign_key_checks = 0",
+		out: &vtgatepb.Session{Autocommit: true},
 	}, {
 		in:  "set skip_query_plan_cache = 1",
 		out: &vtgatepb.Session{Autocommit: true, Options: &querypb.ExecuteOptions{SkipQueryPlanCache: true}},