diff --git a/packages/stores/bun-sql/index.js b/packages/stores/bun-sql/index.js
index 346708d..50f361f 100644
--- a/packages/stores/bun-sql/index.js
+++ b/packages/stores/bun-sql/index.js
@@ -30,6 +30,11 @@ export class BunSqlIdempotencyStore {
    */
   isMySQL;
 
+  /**
+   * @type {boolean}
+   */
+  isPostgres;
+
   /**
    * @param {string} connectionString - Database connection string or path
    * @param {BunSqlIdempotencyStoreOptions} [options]
@@ -37,6 +42,7 @@ export class BunSqlIdempotencyStore {
   constructor(connectionString, options = {}) {
     this.isSqlite = this.isSqliteConnection(connectionString);
     this.isMySQL = this.isMySqlConnection(connectionString);
+    this.isPostgres = this.isPostgresConnection(connectionString);
 
     if (this.isSqlite) {
       const sqlitePath = this.normalizeSqlitePath(connectionString);
@@ -118,6 +124,17 @@ export class BunSqlIdempotencyStore {
     return lower.includes("mysql") || lower.includes("mariadb");
   }
 
+  /**
+   * Check if connection string is PostgreSQL
+   * @param {string} [connectionString]
+   * @returns {boolean}
+   */
+  isPostgresConnection(connectionString) {
+    if (!connectionString) return false;
+    const lower = connectionString.toLowerCase();
+    return lower.includes("postgres") || lower.includes("postgresql");
+  }
+
   /**
    * Initialize database schema with tables and indexes
    * @private
@@ -261,8 +278,12 @@ export class BunSqlIdempotencyStore {
         byFingerprint: this.parseRecord(byFingerprintRow)
       };
     } else {
-      await this
-        .db`DELETE FROM idempotency_records WHERE expires_at <= ${Date.now()}`;
+      // PostgreSQL doesn't support LIMIT in DELETE, use subquery
+      const deleteSql = this.isPostgres
+        ? "DELETE FROM idempotency_records WHERE key IN (SELECT key FROM idempotency_records WHERE expires_at <= $1 LIMIT 10)"
+        : "DELETE FROM idempotency_records WHERE expires_at <= ? LIMIT 10";
+      const deleteParams = this.isPostgres ? [Date.now()] : [Date.now()];
+      await this.db.unsafe(deleteSql, deleteParams);
 
       const keyColumn = this.isMySQL ? "`key`" : '"key"';
       const paramPlaceholder = this.isMySQL ? "?" : "$1";
diff --git a/packages/stores/mysql/deno-mysql.js b/packages/stores/mysql/deno-mysql.js
index 38ec2d0..8492846 100644
--- a/packages/stores/mysql/deno-mysql.js
+++ b/packages/stores/mysql/deno-mysql.js
@@ -126,7 +126,7 @@ export class MysqlIdempotencyStore {
    */
   async lookup(key, fingerprint) {
     await this.client.execute(
-      "DELETE FROM idempotency_records WHERE expires_at <= ?",
+      "DELETE FROM idempotency_records WHERE expires_at <= ? LIMIT 10",
       [Date.now()]
     );
 
diff --git a/packages/stores/mysql/node-mysql.js b/packages/stores/mysql/node-mysql.js
index a1253c8..01648db 100644
--- a/packages/stores/mysql/node-mysql.js
+++ b/packages/stores/mysql/node-mysql.js
@@ -89,7 +89,7 @@ export class MysqlIdempotencyStore {
    */
   async lookup(key, fingerprint) {
     await this.pool.query(
-      `DELETE FROM \`${this.tableName}\` WHERE expires_at <= ?`,
+      `DELETE FROM \`${this.tableName}\` WHERE expires_at <= ? LIMIT 10`,
       [Date.now()]
     );
 
diff --git a/packages/stores/postgres/index.js b/packages/stores/postgres/index.js
index 2af46a2..a9dda09 100644
--- a/packages/stores/postgres/index.js
+++ b/packages/stores/postgres/index.js
@@ -113,8 +113,9 @@ export class PostgresIdempotencyStore {
    * @returns {Promise<{byKey: IdempotencyRecord | null, byFingerprint: IdempotencyRecord | null}>}
    */
   async lookup(key, fingerprint) {
+    // Use subquery with LIMIT since PostgreSQL doesn't support LIMIT in DELETE directly
     await this.pool.query(
-      `DELETE FROM ${this.quotedSchemaIdentifier}.idempotency_records WHERE expires_at <= $1`,
+      `DELETE FROM ${this.quotedSchemaIdentifier}.idempotency_records WHERE key IN (SELECT key FROM ${this.quotedSchemaIdentifier}.idempotency_records WHERE expires_at <= $1 LIMIT 10)`,
       [Date.now()]
     );