On Supporting Efficient Snapshot Isolation for Hybrid Workloads with Multi-Versioned Indexes
On Supporting Efficient Snapshot Isolation for Hybrid Workloads with Multi-Versioned Indexes
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DOI：
10.14778/3364324.3364334
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发表时间：
2019-10
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影响因子：
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通讯作者：
Yihan Sun;G. Blelloch;Wan Shen Lim;Andrew Pavlo
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文献类型：
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作者：
Yihan Sun;G. Blelloch;Wan Shen Lim;Andrew Pavlo
现代数据驱动的应用程序要求数据库支持快速的分析查询，同时经历快速更新（通常称为混合交易分析处理（HTAP））。在数据库管理系统（DBMS）中实现快速查询和更新是一项挑战，因为优化改善分析查询可能会导致更新的开销。一种解决方案是使用快照隔离（SI）进行多次并发控制（MVCC），以允许读者无论同意作家如何取得进步。在本文中，我们提出了平行的二进制树（P-Tree）索引结构，以实现多项内存中HTAP DBMS的SI和MVCC。 p-树在其核心上是基于纯（不可变的）数据结构，这些数据结构使用路径复印进行快速多次化的更新。他们支持树嵌套以提高OLAP性能，同时仍允许有效的更新。数据结构还可以实现对索引及其基础表的批量操作的并行算法。我们评估了OLTP和OLAP基准测试的p-树，并将其与最先进的数据结构和DBMS进行比较。我们的实验表明，P-Trees的表现要优于YCSB工作负载的许多并发数据结构，并且比现有DBMS的分析查询快4--9 x，同时还可以实现合理的吞吐量。
Modern data-driven applications require that databases support fast analytical queries while undergoing rapid updates---often referred to as Hybrid Transactional Analytical Processing (HTAP). Achieving fast queries and updates in a database management system (DBMS) is challenging since optimizations to improve analytical queries can cause overhead for updates. One solution is to use snapshot isolation (SI) for multi-version concurrency control (MVCC) to allow readers to make progress regardless of concurrent writers. In this paper, we propose the Parallel Binary Tree (P-Tree) index structure to achieve SI and MVCC for multicore in-memory HTAP DBMSs. At their core, P-Trees are based on pure (immutable) data structures that use path-copying for updates for fast multi-versioning. They support tree nesting to improve OLAP performance while still allowing for efficient updates. The data structure also enables parallel algorithms for bulk operations on indexes and their underlying tables. We evaluate P-Trees on OLTP and OLAP benchmarks, and compare them with state-of-the-art data structures and DBMSs. Our experiments show that P-Trees outperform many concurrent data structures for the YCSB workload, and is 4--9 x faster than existing DBMSs for analytical queries, while also achieving reasonable throughput for simultaneous transactional updates.