Question: Does Redis support transactions?

Answer

Yes, Redis supports transactions via the MULTI/EXEC commands. Transactions in Redis are used to group a set of commands together, which can be executed atomically as a single transaction.

The basic syntax for a Redis transaction is as follows:

MULTI
<commands>
EXEC

Here's an example of how a transaction would work in Redis:

MULTI
SET key1 "value1"
SET key2 "value2"
EXEC

In this example, we're setting two keys (key1 and key2) to two values (value1 and value2). These commands are grouped together inside the transaction block (MULTI and EXEC) and will be executed atomically.

Redis also provides a feature called WATCH, which allows you to ensure that a transaction executes only if specific conditions (such as a particular value of a key) are met. Here's an example of using WATCH with a transaction:

WATCH key1
val = GET key1
val = val + 1
MULTI
SET key1 $val
EXEC

In this example, we're incrementing the value of key1 by one, but only if it hasn't been modified by another client while we were executing the transaction. The WATCH command tells Redis to monitor changes to key1, and the transaction block will only execute if key1 has not been modified since the WATCH command was issued.

Transactions in Redis provide a powerful way to atomically execute multiple commands, ensuring consistency and reliability in your database operations.