PostgreSQL通过顺序扫描、索引扫描和位图扫描等不同策略读取数据。表以8KB页面存储，每个元组包含可见性信息。顺序扫描逐页读取，索引扫描通过索引查找，位图扫描先构建位图再读取。可见性图优化提升性能，降低CPU开销。选择扫描策略时，PostgreSQL利用成本模型评估最佳方案。

It is 3 AM. A rogue DELETE just wiped 500,000 customer records. Traditional recovery takes hours and risks collateral damage. This guide shows you how to recover accidental DELETEs and UPDATEs in...

In PostgreSQL, a DELETE operation does not immediately erase data from disk. The MVCC mechanism retains deleted rows as dead tuples, and reading these dead tuples is one viable approach to data...

I'm proposing a very ambitious patch set for PostgreSQL 19. Only time will tell whether it ends up in the release, but I can't resist using this space to give you a short demonstration of what it...

© Laurenz Albe 2026 PostgreSQL has supported the (non-standard) ON CONFLICT clause for the INSERT statement since version 9.5. In v19, commit 88327092ff added ON CONFLICT ... DO SELECT. A good...

A while ago, I wrote about the index corruption that you can get after an operating system upgrade, and recently I detailed how to keep the pain of having to rebuild indexes minimal. Since this is...

我成功将PostgreSQL实例升级到18版，记录了升级过程中的数据快照和配置调整，计划在下次直接更新主服务器。

A migration case with only a JAR and no source code shows why Oracle syntax compatibility is not always a fake requirement, and how IvorySQL + Pigsty can absorb legacy debt at low cost.

2026年2月9日，Álvaro Herrera 提交补丁，允许按进程类型设置 log_min_messages，支持以逗号分隔的级别列表，兼容旧版本，方便开发者调试。

2026年2月3日，藤井正雄在psql中新增了转义符%i，用于显示连接服务器的热备状态。若服务器为热备模式，则显示为standby，反之则为primary。这一改进有助于数据库管理员快速识别数据库角色，提高工作效率。