Transaction

I recently read Microsoft’s 2015 VLDB paper, Real-Time Analytical Processing with SQL Server [1]. SQL Server was among the earlier products to ship and productionize an HTAP row/column update design. Row-store (row-wise index) tradeoffs for OLTP are well understood; efficient millisecond-scale column store updates have several designs in the wild—Kudu [2], Positional Delta Tree [3], and others—but they receive far less discussion than row stores. After a careful review of SQL Server’s approach, I find it worth sharing....

This article covers transaction isolation in TokuDB. The source implementation is complex; for clarity, we focus on the most essential parts and omit minor details. Background In traditional relational databases (Oracle, MySQL, SQL Server, and others), transactions are central to both engineering and discussion. The core properties of a transaction are ACID. A (atomicity) means a transaction’s sub-operations have only two outcomes: all succeed on commit, or all are undone on rollback....