Transactions, MVCC and Locking
A single-node transaction is hard enough. This part covers what changes when a transaction spans every segment in the cluster.
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Chapter 9
Transactions and Isolation in Apache Cloudberry
The transaction manager, the XID lifecycle and CLOG, the isolation levels Cloudberry actually enforces, and where distributed serializability stops.
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Chapter 10
MVCC, Snapshots and Vacuum in Apache Cloudberry
Row visibility, the transaction horizon, distributed snapshots and the distributed log, freezing and XID wraparound, and rebuilding tables and indexes.
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Chapter 11
Locks and the Global Deadlock Detector in Cloudberry
Heavyweight and row-level locks, multixacts, local deadlock detection, and the global deadlock detector that makes cross-segment deadlocks survivable.
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Chapter 12
Distributed Transactions and 2PC in Apache Cloudberry
How Cloudberry commits across segments — cdbtm, the DtxState and DtxContext state machines, distributed commit ordering, and DTX recovery after a crash.