Tencent's Database R&D team supports internal services such as WeChat Pay, WeChat Red Packets, Tencent Advertising, and Tencent Music, and provides external support on Tencent Cloud for TencentDB products like CynosDB, CDB, and TDSQL. This public account aims to promote and share professional database knowledge, growing together with database enthusiasts.
This article provides a comprehensive overview of the MySQL Test Run (MTR) framework, detailing its two-part architecture consisting of Perl scripts for control flow and C++ binaries for test execution, along with the complete execution process and framework design.
This article provides a comprehensive overview of InnoDB's buffer pool, detailing its role as a data cache, the underlying data structures such as instances, chunks, and blocks, the page lifecycle from allocation to flushing, and discusses limitations of the default page‑cleaner implementation along with Percona's enhancements.
This article provides a comprehensive overview of MonetDB, covering its origins at CWI, column‑oriented storage with BATs, memory‑mapped and vectorized execution, three‑layer system architecture, cache‑aware optimizations such as vector operations and radix‑partitioned hash joins, as well as its limitations and reference sources.
This article examines MySQL's event scheduler architecture, detailing its core classes, execution flow, heap insertion and deletion algorithms, and investigates two critical bugs—slow‑log misrecording and delayed event execution—while proposing concrete fixes to improve reliability.
This article explains Elasticsearch X‑Pack's machine‑learning capabilities, covering supervised and unsupervised learning concepts, data preparation, task creation types, architecture components, data flow, result indices, and provides code examples for configuring and running ML jobs.
MLOG_CHECKPOINT is a mechanism in MySQL InnoDB crash recovery that ensures complete mapping between space IDs and file paths by supplementing missing MLOG_FILE_NAME records, addressing gaps that could occur between checkpoints and subsequent file modifications.
This article explains how MongoDB's nearest mode achieves proximity‑aware reads across multiple data centers by analyzing the internal mongos and driver code, detailing latency collection, smoothing algorithms, node selection logic, and providing configuration recommendations for latency‑sensitive workloads.
This article explains InnoDB's Multi-Version Concurrency Control (MVCC) architecture, detailing row formats, undo log types, ReadView visibility rules, purge processes, and related concepts such as semi-consistent reads and index condition pushdown, with code examples and diagrams illustrating each mechanism.
This article provides a comprehensive overview of InnoDB's file structure, covering physical organization from pages to tablespaces, logical structure including segments and indexes, and file management processes.
The article explains MySQL 8.0’s new iterator‑based executor, detailing the underlying iterator model, its advantages over the legacy executor, the specific RowIterator classes introduced, supported query features, and future enhancements for more advanced algebraic operations.
