simplify code; adding comments

Signed-off-by: Shlomi Noach <[email protected]>

go/vt/schema/name.go

@@ -33,6 +33,7 @@ const (
 )
 
 var (
+	// internalTableNameRegexp parses new intrnal table name format, e.g. _vt_hld_6ace8bcef73211ea87e9f875a4d24e90_20200915120410_
 	internalTableNameRegexp = regexp.MustCompile(InternalTableNameExpression)
 )
 

go/vt/schema/online_ddl.go

@@ -471,10 +471,10 @@ func OnlineDDLToGCUUID(uuid string) string {
 // by pt-online-schema-change.
 // There is no guarantee that the tables _was indeed_ generated by an online DDL flow.
 func IsOnlineDDLTableName(tableName string) bool {
-	// Try new naming format (e.g. `_vt_hld_6ace8bcef73211ea87e9f875a4d24e90_20200915120410_`):
+	// Try new naming format (e.g. `_vt_vrp_6ace8bcef73211ea87e9f875a4d24e90_20200915120410_`):
 	// The new naming format is accepted in v19, and actually _used_ in v20
 	if isInternal, hint, _, _, _ := AnalyzeInternalTableName(tableName); isInternal {
-		return isInternal && onlineDDLInternalTableHintsMap[hint]
+		return onlineDDLInternalTableHintsMap[hint]
 	}
 
 	if onlineDDLGeneratedTableNameRegexp.MatchString(tableName) {

go/vt/schema/tablegc.go

@@ -45,7 +45,8 @@ const (
 )
 
 const (
-	GCTableNameExpression    string = `^_vt_(HOLD|PURGE|EVAC|DROP)_([0-f]{32})_([0-9]{14})$`
+	GCTableNameExpression string = `^_vt_(HOLD|PURGE|EVAC|DROP)_([0-f]{32})_([0-9]{14})$`
+	// NewGCTableNameExpression parses new intrnal table name format, e.g. _vt_hld_6ace8bcef73211ea87e9f875a4d24e90_20200915120410_
 	NewGCTableNameExpression string = `^_vt_(hld|prg|evc|drp)_([0-f]{32})_([0-9]{14})_$`
 )