RUST CHINA CONF 2023 第三届中国 Rust 开发者大会 6.17-6.18 @Shanghai ## Await-Tree Async Rust 可观测性的灵丹妙药 赵梓淇 Bugen Zhao RisingWave ## Await-Tree Async Rust 可观测性的灵丹妙药   Await-Tree 的应用与真实案例 的应用与真实案例 ## Await-Tree Async Rust 可观测性的灵丹妙药 1 回顾 Async Rust 的设计与痛点  Await-Tree 的设计原理与实现 ![Image](/uploads/documents/1/6/1

Git project: the working tree, the staging area, and the Git directory.  Figure 6. Working tree, staging area, and Git directory directory The working tree is a single checkout of one version of the project. These files are pulled out of the compressed database in the Git directory and placed on disk for you to use or modify. another computer. The basic Git workflow goes something like this: 1. You modify files in your working tree. 2. You selectively stage just those changes you want to be part of your next commit, which adds

emit onTurnDone event. - ApplicationRef - Triggered by onTurnDone and checks the whole component tree for change detections. - ChangeDetectorRef - checks only the current component and its children. component has a change detector. - Change detector propagates bindings from top to leaves. ☐ Directed tree: More performant, predictable, and debuggable than cycles. - Hundred of thousands of checks per few application. - Detect template errors early. • Used by Mobile Frameworks: Ionic & NativeScript. - Tree Shaking: Remove any dead code not used in final bundle by WebPack. ## Angular Universal - Pre-compiles

独立运行，通常在 PieCloudDB 控制节点上 • 按需启动数据源(插件)导出 • 发送 SQL 语句到 PieCloudDB 控制节点 • 收集执行结果，记录进度和错误信息 • INSERT/MERGE 模式 ## PieCloudDB ETL方案总体设计与实现 • INSERT 模式，支持单纯导入场景 • 与现有数据没有逻辑关联的时序数据流 ## PieCloudDB ETL方案总体设计与实现 插入历史表，支持断点续传 ☐ ☐ ☐ INSERT INTO history SELECT meta FROM foreign_table ## PieCloudDB ETL方案总体设计与实现 • Merge/Upsert 模式，支持 CDC 场景 • 数据需要包含操作字段（OP），即 INSERT/UPDATE/DELETE - 数据需要包含逻辑主键（LPK），当逻辑主键不存在时做插入，已存在时做更新或者删除 做更新或者删除 • 数据需要包含顺序键（OK），以决定操作生效的顺序 • 数据可以重复，但不可以有事务逻辑错误 ## PieCloudDB ETL方案总体设计与实现 ## • Merge/Upsert 模式，步骤1 将数据解析完成，导入与目标表类型相同的临时表中 ☐ ☐ ☐ SELECT r.a, r.b+r.c, func(r.d) ... FROM (SELECT meta, raw)

command 1.11 rm command 1.12 Copying a file using cp command 1.13 Renaming or moving a file 1.14 tree command 1.15 wc command 1.16 less command 1.17 echo command 1.18 Redirecting the command output fedora 75 Jun 25 04:33 nothello.txt ### 1.14 tree command tree command prints the directory structure in a nice visual tree design way. [babai@kdas-laptop ~]$ tree - code - Desktop - dir1 - dir2 - Documents Documents - Downloads - Music - Pictures - terminall.png - Public - Templates - Videos Note: The tree command may not be installed on your system by default, you can install it later after reading the package

Based on WiscKey paper by Uni Wisconsin-Madison. Separates keys from values. Stores keys in LSM tree. Stores value in value log. Write to Value Log Write value, get pointer. More keys per table ’ alt=‘OCR图片’/> ’ alt=‘OCR图片’/> Typical Badger setup ’ alt=‘OCR图片’/> Advantages of smaller LSM tree Can be kept in RAM. Low read amplification (fewer lookups). Low write amplification (fewer compactions) of keys. Usenet Express Hundreds of terabytes of data. Few gigabytes of LSM tree. Reads in Badger: LSM tree Memtable (64 MB) L0(256MB) $$ \square \square \square \square $$ L1(256MB) $$ \square

array of Work Contracts (each with their own logic and, if needed, data, queue, etc) ☐ A Signal Tree (which has as many leaf nodes as there are work contracts in the group) • Threads are brought to Contracts  ## The Signal Tree: • Lock Free with most operations also wait free ☐ Allows MT traversal without locks and therefore Fairness|0.25|0.15|0.04|0.01| ## Where is this improvement coming from? Signal Trees ## The Signal Tree: • Lock Free with most operations also wait free: ○ Allows MT traversal without locks and therefore

tinypng:也是将24位png文件转化为更小有索引的8位图片，同时所有非必要的metadata也会被剥离掉 ## tree shaking(摇树优化)复习 概念：1 个模块可能有多个方法，只要其中的某个方法使用到了，则整个文件都会被打到 bundle 里面去，tree shaking 就是只把用到的方法打入 bundle，没用到的方法会在 uglify 阶段被擦除掉。 使用：webpack com/polyfill_service/v2/polyfill.min.js?unknown=polyfill&features=Promise,Map,Set ## 体积优化策略总结 Scope Hoisting Tree-shaking 公共资源分离 图片压缩 动态 Polyfill ## ☐ ☐ ☐ ☐ ## 扫码试看/订阅 《玩转webpack》

Information Systems) objects to be stored in the database. PostGIS includes support for GiST-based R-Tree spatial indexes, and functions for analysis and processing of GIS objects. ![OCR图片](/uploads/doc PgAdmin III 1.14+ will also provide this information in the extensions section of the database browser tree and will even allow upgrade or uninstall by right-clicking. If you have the extensions available z-value will be regarded as "any value" passed Test: test_rect_tree_contains_point ...passed Test: test_rect_tree_intersects_tree ...passed Test: test_lwgeom_segmentize2d ...NOTICE: ptarray.c:448