perf(db): drop redundant single-column indexes

backend/ent/schema/auth_identity.go

@@ -91,7 +91,6 @@ func (AuthIdentity) Edges() []ent.Edge {
 func (AuthIdentity) Indexes() []ent.Index {
 	return []ent.Index{
 		index.Fields("provider_type", "provider_key", "provider_subject").Unique(),
-		index.Fields("user_id"),
 		index.Fields("user_id", "provider_type"),
 	}
 }

backend/ent/schema/channel_monitor.go

@@ -107,7 +107,6 @@ func (ChannelMonitor) Edges() []ent.Edge {
 func (ChannelMonitor) Indexes() []ent.Index {
 	return []ent.Index{
 		index.Fields("enabled", "last_checked_at"),
-		index.Fields("provider"),
 		index.Fields("provider", "api_mode"),
 		index.Fields("group_name"),
 		index.Fields("template_id"),

backend/ent/schema/payment_audit_log.go

@@ -8,7 +8,6 @@ import (
 	"entgo.io/ent/dialect/entsql"
 	"entgo.io/ent/schema"
 	"entgo.io/ent/schema/field"
-	"entgo.io/ent/schema/index"
 )
 
 // PaymentAuditLog holds the schema definition for the PaymentAuditLog entity.
@@ -48,7 +47,5 @@ func (PaymentAuditLog) Fields() []ent.Field {
 }
 
 func (PaymentAuditLog) Indexes() []ent.Index {
-	return []ent.Index{
-		index.Fields("order_id"),
-	}
+	return []ent.Index{}
 }

backend/ent/schema/usage_log.go

@@ -193,13 +193,7 @@ func (UsageLog) Edges() []ent.Edge {
 // Indexes 定义数据库索引，优化查询性能。
 func (UsageLog) Indexes() []ent.Index {
 	return []ent.Index{
-		index.Fields("user_id"),
-		index.Fields("api_key_id"),
-		index.Fields("account_id"),
 		index.Fields("group_id"),
-		index.Fields("subscription_id"),
-		index.Fields("created_at"),
-		index.Fields("model"),
 		index.Fields("requested_model"),
 		index.Fields("request_id"),
 		// 复合索引用于时间范围查询

backend/internal/repository/migrations_runner.go

@@ -465,8 +465,9 @@ func validateMigrationExecutionMode(name, content string) (bool, error) {
 		}
 
 		if strings.Contains(normalizedStmt, "CONCURRENTLY") {
-			isCreateIndex := strings.Contains(normalizedStmt, "CREATE") && strings.Contains(normalizedStmt, "INDEX")
-			isDropIndex := strings.Contains(normalizedStmt, "DROP") && strings.Contains(normalizedStmt, "INDEX")
+			// 按首关键字判定，避免索引名含 "created" 等子串使 DROP 被误判为 CREATE。
+			isCreateIndex := strings.HasPrefix(normalizedStmt, "CREATE") && strings.Contains(normalizedStmt, "INDEX")
+			isDropIndex := strings.HasPrefix(normalizedStmt, "DROP") && strings.Contains(normalizedStmt, "INDEX")
 			if !isCreateIndex && !isDropIndex {
 				return false, errors.New("*_notx.sql currently only supports CREATE/DROP INDEX CONCURRENTLY statements")
 			}

backend/internal/repository/migrations_runner_notx_test.go

@@ -49,6 +49,12 @@ DROP INDEX CONCURRENTLY IF EXISTS idx_b;
 		require.True(t, nonTx)
 		require.NoError(t, err)
 	})
+
+	t.Run("notx迁移允许DROP名称含created的索引", func(t *testing.T) {
+		nonTx, err := validateMigrationExecutionMode("143_drop_idx_notx.sql", "DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_created_at;")
+		require.True(t, nonTx)
+		require.NoError(t, err)
+	})
 }
 
 func TestApplyMigrationsFS_NonTransactionalMigration(t *testing.T) {

backend/migrations/143_drop_redundant_indexes_notx.sql

@@ -0,0 +1,16 @@
+-- 143：删除被云数据库巡检标记为冗余的单列索引（均为既有复合/唯一索引的最左前缀，可被覆盖）。
+-- 采用 *_notx + DROP INDEX CONCURRENTLY 避免在高写入表上持有排他锁；IF EXISTS 保证可重复执行。
+
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_user_id;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_api_key_id;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_account_id;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_model;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_subscription_id;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_logs_created_at;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_dashboard_hourly_users_bucket_start;
+DROP INDEX CONCURRENTLY IF EXISTS idx_usage_dashboard_daily_users_bucket_date;
+DROP INDEX CONCURRENTLY IF EXISTS idx_payment_audit_logs_order_id;
+DROP INDEX CONCURRENTLY IF EXISTS idx_channel_monitors_provider;
+DROP INDEX CONCURRENTLY IF EXISTS auth_identity_migration_reports_type_idx;
+DROP INDEX CONCURRENTLY IF EXISTS auth_identities_user_id_idx;
+DROP INDEX CONCURRENTLY IF EXISTS user_provider_default_grants_user_id_idx;