diff --git a/initialize/migrate/database/02130_add_refer_code_index.down.sql b/initialize/migrate/database/02130_add_refer_code_index.down.sql
new file mode 100644
index 0000000..58bb5a7
--- /dev/null
+++ b/initialize/migrate/database/02130_add_refer_code_index.down.sql
@@ -0,0 +1,2 @@
+-- Remove index on refer_code column
+ALTER TABLE `user` DROP INDEX `idx_refer_code`;
diff --git a/initialize/migrate/database/02130_add_refer_code_index.up.sql b/initialize/migrate/database/02130_add_refer_code_index.up.sql
new file mode 100644
index 0000000..8ed95a2
--- /dev/null
+++ b/initialize/migrate/database/02130_add_refer_code_index.up.sql
@@ -0,0 +1,2 @@
+-- Add index on refer_code column for faster lookup
+ALTER TABLE `user` ADD INDEX `idx_refer_code` (`refer_code`);