Self-review

Signed-off-by: Rohit Nayak <rohit@planetscale.com>

Author: rohit-nayak-ps

go/vt/proto/binlogdata/binlogdata.pb.go

@@ -684,7 +684,14 @@ func (vs *vstreamer) buildSidecarTablePlan(id uint64, tm *mysql.TableMap) ([]*bi
 	tableName := tm.Name
 	switch tableName {
 	case "resharding_journal":
+		// A journal is a special case that generates a JOURNAL event.
 	case "schema_version":
+		// Generates a Version event when it detects that a schema is stored in the schema_version table.
+
+		// SkipMetaCheck is set during PITR restore: some table metadata is not fetched in that case.
+		if vs.se.SkipMetaCheck {
+			return nil, nil
+		}
 	default:
 		if vs.options == nil {
 			return nil, nil

go/vt/proto/vtgate/vtgate.pb.go

@@ -344,7 +344,7 @@ message RowEvent {
   string keyspace = 3;
   string shard = 4;
   uint32 flags = 5; // https://dev.mysql.com/doc/dev/mysql-server/latest/classbinary__log_1_1Rows__event.html
-  bool is_internal = 6;
+  bool is_internal = 6; // set for sidecardb tables
 }
 
 // FieldEvent represents the field info for a table.
@@ -361,7 +361,7 @@ message FieldEvent {
   // NOTE: because this is the use case, this is ONLY ever set today in
   // vstreams managed by the vstreamManager.
   bool enum_set_string_values = 25;
-  bool is_internal = 26;
+  bool is_internal = 26; // set for sidecardb tables
 }
 
 // ShardGtid contains the GTID position for one shard.

go/vt/vttablet/tabletserver/vstreamer/vstreamer.go

@@ -302,6 +302,7 @@ message VStreamFlags {
   string cells = 4;
   string cell_preference = 5;
   string tablet_order = 6;
+  // When set, all new row events from the `heartbeat` table, in all shards, in the sidecardb will be streamed.
   bool stream_keyspace_heartbeats = 7;
 }