diff --git a/monkeyai/backend/internal/billing/query.sql b/monkeyai/backend/internal/billing/query.sql
index 1efe0f2dd..e9620ad04 100644
--- a/monkeyai/backend/internal/billing/query.sql
+++ b/monkeyai/backend/internal/billing/query.sql
@@ -444,21 +444,24 @@ SELECT
 	COALESCE(t.reserved, 0)::text)
 FROM
     credit_accounts a
-    LEFT JOIN LATERAL (
+    LEFT JOIN (
         SELECT
+            account_id,
             sum(credit_delta) balance
         FROM
             credit_ledger_entries
-        WHERE
-            account_id = a.id) l ON TRUE
-    LEFT JOIN LATERAL (
+        GROUP BY
+            account_id) l ON l.account_id = a.id
+    LEFT JOIN (
         SELECT
+            account_id,
             sum(reserve) reserved
         FROM
             billing_transactions
         WHERE
-            account_id = a.id
-            AND status NOT IN ('settled', 'released', 'rejected')) t ON TRUE
+            status NOT IN ('settled', 'released', 'rejected')
+        GROUP BY
+            account_id) t ON t.account_id = a.id
 WHERE
     a.balance <> COALESCE(l.balance, 0)
     OR a.frozen <> COALESCE(t.reserved, 0)
diff --git a/monkeyai/backend/internal/billing/query_test.go b/monkeyai/backend/internal/billing/query_test.go
new file mode 100644
index 000000000..d15fd65a3
--- /dev/null
+++ b/monkeyai/backend/internal/billing/query_test.go
@@ -0,0 +1,51 @@
+package billing
+
+import (
+	"testing"
+
+	"github.com/chaitin/MonkeyCode/monkeyai/backend/internal/billing/sqlc"
+	"github.com/chaitin/MonkeyCode/monkeyai/backend/internal/resource"
+)
+
+func TestAccountDifferences(t *testing.T) {
+	s, user, model := fixture(t)
+	ctx := t.Context()
+	query := sqlc.New(s.pool)
+	account, err := s.Account(ctx, user)
+	if err != nil {
+		t.Fatal(err)
+	}
+	check := func(want int) []resource.Object {
+		t.Helper()
+		differences, err := resource.DecodeObjects(query.AccountDifferences(ctx))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(differences) != want {
+			t.Fatalf("账户差异数量错误: got=%d want=%d differences=%v", len(differences), want, differences)
+		}
+		return differences
+	}
+
+	check(0)
+	if _, err = s.Begin(ctx, Request{UserID: user, ResourceID: model, Category: "model"}); err != nil {
+		t.Fatal(err)
+	}
+	check(0)
+
+	if _, err = s.pool.Exec(ctx, `UPDATE credit_accounts SET frozen = frozen + 1 WHERE id = $1`, account.ID); err != nil {
+		t.Fatal(err)
+	}
+	differences := check(1)
+	if differences[0].String("account_id") != account.ID || differences[0].String("frozen") == differences[0].String("reserved") {
+		t.Fatalf("未识别冻结额差异: %v", differences[0])
+	}
+
+	if _, err = s.pool.Exec(ctx, `UPDATE credit_accounts SET frozen = frozen - 1, balance = balance - 1 WHERE id = $1`, account.ID); err != nil {
+		t.Fatal(err)
+	}
+	differences = check(1)
+	if differences[0].String("balance") == differences[0].String("ledger_balance") {
+		t.Fatalf("未识别账本余额差异: %v", differences[0])
+	}
+}
diff --git a/monkeyai/backend/internal/billing/sqlc/query.sql.go b/monkeyai/backend/internal/billing/sqlc/query.sql.go
index 53e7c77a4..3762f71fb 100644
--- a/monkeyai/backend/internal/billing/sqlc/query.sql.go
+++ b/monkeyai/backend/internal/billing/sqlc/query.sql.go
@@ -19,21 +19,24 @@ SELECT
 	COALESCE(t.reserved, 0)::text)
 FROM
     credit_accounts a
-    LEFT JOIN LATERAL (
+    LEFT JOIN (
         SELECT
+            account_id,
             sum(credit_delta) balance
         FROM
             credit_ledger_entries
-        WHERE
-            account_id = a.id) l ON TRUE
-    LEFT JOIN LATERAL (
+        GROUP BY
+            account_id) l ON l.account_id = a.id
+    LEFT JOIN (
         SELECT
+            account_id,
             sum(reserve) reserved
         FROM
             billing_transactions
         WHERE
-            account_id = a.id
-            AND status NOT IN ('settled', 'released', 'rejected')) t ON TRUE
+            status NOT IN ('settled', 'released', 'rejected')
+        GROUP BY
+            account_id) t ON t.account_id = a.id
 WHERE
     a.balance <> COALESCE(l.balance, 0)
     OR a.frozen <> COALESCE(t.reserved, 0)
diff --git a/monkeyai/backend/migrations/000007_billing_pending_time_index.down.sql b/monkeyai/backend/migrations/000007_billing_pending_time_index.down.sql
new file mode 100644
index 000000000..4adaea34a
--- /dev/null
+++ b/monkeyai/backend/migrations/000007_billing_pending_time_index.down.sql
@@ -0,0 +1 @@
+DROP INDEX CONCURRENTLY IF EXISTS billing_transactions_pending_time_idx;
diff --git a/monkeyai/backend/migrations/000007_billing_pending_time_index.up.sql b/monkeyai/backend/migrations/000007_billing_pending_time_index.up.sql
new file mode 100644
index 000000000..280babe8a
--- /dev/null
+++ b/monkeyai/backend/migrations/000007_billing_pending_time_index.up.sql
@@ -0,0 +1,3 @@
+CREATE INDEX CONCURRENTLY billing_transactions_pending_time_idx
+    ON billing_transactions(started_at, id)
+    WHERE status NOT IN ('settled', 'released', 'rejected');
diff --git a/monkeyai/backend/migrations/000008_billing_pending_account_index.down.sql b/monkeyai/backend/migrations/000008_billing_pending_account_index.down.sql
new file mode 100644
index 000000000..858bad2d8
--- /dev/null
+++ b/monkeyai/backend/migrations/000008_billing_pending_account_index.down.sql
@@ -0,0 +1 @@
+DROP INDEX CONCURRENTLY IF EXISTS billing_transactions_pending_account_idx;
diff --git a/monkeyai/backend/migrations/000008_billing_pending_account_index.up.sql b/monkeyai/backend/migrations/000008_billing_pending_account_index.up.sql
new file mode 100644
index 000000000..5161796ac
--- /dev/null
+++ b/monkeyai/backend/migrations/000008_billing_pending_account_index.up.sql
@@ -0,0 +1,4 @@
+CREATE INDEX CONCURRENTLY billing_transactions_pending_account_idx
+    ON billing_transactions(account_id)
+    INCLUDE (reserve)
+    WHERE status NOT IN ('settled', 'released', 'rejected');