change the method of initializing slice

callbacks/associations.go

@@ -137,7 +137,7 @@ func SaveAfterAssociations(db *gorm.DB) {
 				}
 
 				if elems.Len() > 0 {
-					assignmentColumns := []string{}
+					assignmentColumns := make([]string, 0, len(rel.References))
 					for _, ref := range rel.References {
 						assignmentColumns = append(assignmentColumns, ref.ForeignKey.DBName)
 					}
@@ -151,7 +151,7 @@ func SaveAfterAssociations(db *gorm.DB) {
 						f = f.Addr()
 					}
 
-					assignmentColumns := []string{}
+					assignmentColumns := make([]string, 0, len(rel.References))
 					for _, ref := range rel.References {
 						if ref.OwnPrimaryKey {
 							fv, _ := ref.PrimaryKey.ValueOf(db.Statement.ReflectValue)
@@ -216,7 +216,7 @@ func SaveAfterAssociations(db *gorm.DB) {
 			}
 
 			if elems.Len() > 0 {
-				assignmentColumns := []string{}
+				assignmentColumns := make([]string, 0, len(rel.References))
 				for _, ref := range rel.References {
 					assignmentColumns = append(assignmentColumns, ref.ForeignKey.DBName)
 				}
@@ -320,7 +320,7 @@ func onConflictOption(stmt *gorm.Statement, s *schema.Schema, selectColumns map[
 	}
 
 	if len(defaultUpdatingColumns) > 0 {
-		var columns []clause.Column
+		columns := make([]clause.Column, 0, len(s.PrimaryFieldDBNames))
 		for _, dbName := range s.PrimaryFieldDBNames {
 			columns = append(columns, clause.Column{Name: dbName})
 		}

callbacks/delete.go

@@ -38,7 +38,7 @@ func DeleteBeforeAssociations(db *gorm.DB) {
 							withoutConditions := false
 
 							if len(db.Statement.Selects) > 0 {
-								var selects []string
+								selects := make([]string, 0, len(db.Statement.Selects))
 								for _, s := range db.Statement.Selects {
 									if s == clause.Associations {
 										selects = append(selects, s)

migrator/migrator.go

@@ -172,7 +172,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 
 			if !hasPrimaryKeyInDataType && len(stmt.Schema.PrimaryFields) > 0 {
 				createTableSQL += "PRIMARY KEY ?,"
-				primaryKeys := []interface{}{}
+				primaryKeys := make([]interface{}, 0, len(stmt.Schema.PrimaryFieldDBNames))
 				for _, field := range stmt.Schema.PrimaryFields {
 					primaryKeys = append(primaryKeys, clause.Column{Name: field.DBName})
 				}
@@ -439,11 +439,12 @@ func buildConstraint(constraint *schema.Constraint) (sql string, results []inter
 		sql += " ON UPDATE " + constraint.OnUpdate
 	}
 
-	var foreignKeys, references []interface{}
+	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
 	for _, field := range constraint.ForeignKeys {
 		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
 	}
 
+	references := make([]interface{}, 0, len(constraint.References))
 	for _, field := range constraint.References {
 		references = append(references, clause.Column{Name: field.DBName})
 	}

schema/naming.go

@@ -88,7 +88,7 @@ var (
 )
 
 func init() {
-	var commonInitialismsForReplacer []string
+	commonInitialismsForReplacer := make([]string, 0, len(commonInitialisms))
 	for _, initialism := range commonInitialisms {
 		commonInitialismsForReplacer = append(commonInitialismsForReplacer, initialism, strings.Title(strings.ToLower(initialism)))
 	}

schema/utils.go

@@ -157,8 +157,7 @@ func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map
 // GetIdentityFieldValuesMapFromValues get identity map from fields
 func GetIdentityFieldValuesMapFromValues(values []interface{}, fields []*Field) (map[string][]reflect.Value, [][]interface{}) {
 	resultsMap := map[string][]reflect.Value{}
-	results := [][]interface{}{}
+	results := make([][]interface{}, 0, len(values))
-
 	for _, v := range values {
 		rm, rs := GetIdentityFieldValuesMap(reflect.Indirect(reflect.ValueOf(v)), fields)
 		for k, v := range rm {