belliottsmith commented on code in PR #4572: URL: https://github.com/apache/cassandra/pull/4572#discussion_r2731449701
########## doc/modules/cassandra/pages/developing/cql/transactions.adoc: ########## @@ -0,0 +1,985 @@ += Accord Transactions +:page-nav-title: Transactions + +Accord provides strong consistency and ACID guarantees for Cassandra operations. +When enabled on a table, **all CQL operations automatically execute through Accord** - no code changes required. +For complex multi-step operations, explicit transaction syntax (`BEGIN TRANSACTION ... COMMIT TRANSACTION`) allows you to read, apply conditions, and write atomically across multiple partitions and tables. + +== Overview + +=== Key Benefits + +* **Automatic Strong Consistency**: Normal CQL reads and writes become linearizable when `transactional_mode='full'` +* **ACID Guarantees**: Atomicity, Consistency, Isolation, and Durability across multiple operations +* **Multi-Partition Consistency**: Coordinate updates across different partition keys +* **Multi-Table Support**: Update multiple tables atomically within a single transaction +* **Complex Business Logic**: Support for conditional operations with multiple steps + +=== When to Use Explicit Transactions + +While normal CQL operations are automatically transactional with `transactional_mode='full'`, use explicit `BEGIN TRANSACTION ... COMMIT TRANSACTION` syntax when you need: + +* **Read-Modify-Write Patterns**: Check a condition before making changes +* **Complex Business Logic**: Multi-step operations that must be atomic +* **Cross-Partition Operations**: Updates that span multiple partition keys +* **Multi-Table Atomicity**: Ensure related changes across tables succeed or fail together + +=== Safety & Consistency + +Accord ensures data integrity through: + +* **Snapshot Isolation**: Each transaction sees a consistent snapshot of data Review Comment: We provide stronger guarantees than "snapshot isolation". Transactions are `strict serializable`; snapshot isolation is typically an implementation of `read committed` isolation. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
