db/users: add indexes on users.pubkey and users.username

src/db/migrations/004_add_user_indexes.ts

@@ -0,0 +1,20 @@
+import { Kysely } from '@/deps.ts';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createIndex('idx_users_pubkey')
+    .on('users')
+    .column('pubkey')
+    .execute();
+
+  await db.schema
+    .createIndex('idx_users_username')
+    .on('users')
+    .column('username')
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropIndex('idx_users_pubkey').execute();
+  await db.schema.dropIndex('idx_users_username').execute();
+}