📋

Description

This error occurs when an operation that is not permitted within a multi-document transaction is attempted. MongoDB multi-document transactions have specific limitations on the types of commands and operations that can be executed within their scope, often related to schema modifications or certain administrative tasks.

💬

Error Message

Operation Not Supported In Transaction

🔍

Known Causes

3 known causes

⚠️

Attempting DDL Operations

Executing schema modification commands, such as creating or dropping collections and indexes, is not allowed within multi-document transactions.

⚠️

Executing Non-Transactional Commands

Certain administrative commands, like `createUser` or `shutdown`, cannot be run inside a transaction and will trigger this error.

⚠️

Unsupported Read/Write Operations

Some specific read or write operations, particularly those that implicitly create new collections or databases, are disallowed within the context of a transaction.

🛠️

Solutions

3 solutions available

1. Move Operation Outside Transaction medium

Some operations can't run in transactions

1

Common unsupported operations in transactions

// These DON'T work in transactions:
db.createCollection("new")  // DDL operations
db.collection.createIndex()  // Index operations
db.collection.drop()         // Collection operations
db.collection.aggregate([{$out: "other"}])  // $out/$merge stages

2

Run DDL before/after transaction

// Create collection first
db.createCollection("orders");

// Then use transaction for data operations
const session = client.startSession();
session.startTransaction();
await db.orders.insertOne({ item: "test" }, { session });
await session.commitTransaction();

2. Handle $out/$merge Differently medium

Output stages can't be in transactions

1

Use two-step approach

// Instead of $out in transaction:
const session = client.startSession();
session.startTransaction();

// Step 1: Get results into array (in transaction)
const results = await db.source.aggregate([
  { $match: { status: 'active' } },
  { $project: { name: 1 } }
], { session }).toArray();

// Step 2: Insert results (still in transaction)
await db.target.insertMany(results, { session });

await session.commitTransaction();

3. Use Read-Only Aggregations easy

Aggregations without write stages work

1

Read-only aggregation in transaction

const session = client.startSession();
session.startTransaction();

// This works (no $out/$merge):
const results = await db.orders.aggregate([
  { $match: { user_id: userId } },
  { $lookup: { from: 'products', ... } },
  { $group: { _id: '$status', total: { $sum: 1 } } }
], { session }).toArray();

await session.commitTransaction();

🔗

Related Errors

5 related errors

MongoDB Error 263: Unsupported Operation in Transaction