Transactions

Transactions allow multiple clients to concurrently read and write data in the database with ACID guarantees. By virtue of using FoundationDB under the hood Tigris employs ACID transactions implicitly for all operations.

Following are some of the properties of transactions in Tigris:

• All operations are always atomic, durable and leave the database in a consistent state
• Transactions are executed using optimistic concurrency control which ensures that documents don't need to be locked when updating
• Transactions are globally ordered and provide strict serializability guarantee

Distributed ACID Transactions

Transactions in Tigris work across collections and documents without any restrictions or performance penalty.

How to use transactions

Transactions in Tigris can be executed in an interactive manner. You can begin a transaction and perform multiple operations inside this transaction's context. Commit provides all or nothing semantics by ensuring that there are no partial updates in the database if a transaction fails.

await db.transact(async (tx) => {
  // read user 1
  const user1 = await users.findOne(
    {
      filter: { userId: 1 },
    },
    tx
  );

  // read user 2
  const user2 = await users.findOne(
    {
      filter: { userId: 2 },
    },
    tx
  );

  if (user1 === undefined || users2 === undefined) {
    throw new Error("User(s) not found"); // This will auto-rollback transaction
  }

  // deduct balance from user1
  let result = await users.updateOne(
    {
      filter: { userId: user1.userId },
      fields: { balance: user1.balance - 100 },
    },
    tx
  );

  if (!result?.modifiedCount) {
    throw new Error(`Failed to update user's balance: ${result}`); // This will auto-rollback transaction
  }

  // add balance to user2
  result = await users.updateOne(
    {
      filter: { userId: user2.userId },
      fields: { balance: user2.balance + 100 },
    },
    tx
  );

  if (!result?.modifiedCount) {
    throw new Error(`Failed to update user's balance: ${result}`); // This will auto-rollback transaction
  }
});

See the language-specific sections for more examples of Transactions:

• Transactions in TypeScript
• Transactions in Go
• Transactions in Java

Learn more about the internals of transactions in Tigris and how they compare to MongoDB transactions.