1 概述 2 pg_class 3 namespace 4 unique_index_violation 5 duplicate 1 概述 GP 提供了 gpcheckcat 用于在集群内检查系统表。 | 检查项 || 描述 || Utility 模式 || 复合查询 || 错误等级 | |———————|————————————————————————-|————|——|——| | pg_class || Check pg_class entry that does not have any correspond pg_attribute entry || Y...

1 Data structures 1.1 Slice Table 2 PostgresMain 2.1 Call graph (QE): 2.2 QD 3 Receiver 4 Sender 1 Data structures 1.1 Slice Table @startuml class SliceTable { + NodeTag type + int localSlice + int numSlices + ExecSlice slices + bool hasMotions + int instrument_options + uint32 ic_instance_id } note right of SliceTable::localSlice Index of the slice to execute end note note right of SliceTable::slices Array of slices, indexed...

1 TODO VMem 2 Resource Group Control 2.1 Bypass 2.2 Fixed Mem 2.3 Memory Limit TODO 1 VMem 2 Resource Group Control ResourceGroupGetQueryMemoryLimit(void) 用于获取内存限制的绝对大小 （非百分比） 2.1 Bypass 绕开资源限制模式 Enabled when: gp_resource_group_bypass is true: guc_gp.c { {"gp_resource_group_bypass", PGC_USERSET, RESOURCES, gettext_noop("If the value is true, the query in...

1 IP Fragmentation Settings 2 Networking 本文为摘录，原文为： https://docs.vmware.com/en/VMware-Tanzu-Greenplum/6/greenplum-database/GUID-install_guide-prep_os.html 1 IP Fragmentation Settings IP Fragmentation Settings When the Greenplum Database interconnect uses UDP (the default), the network interface card controls IP packet fragmentation and reassemblies. If the UDP message size is larger than the size of the maximum transmission unit (MTU) of a network, the IP layer fragments the message. (Refer to...

1 使用高速硬件，降低节点间的延迟 2 尽量降低网络中断的次数。 3 尽量提高每一个数据包的有效载荷 本文为摘录，原文为： attachments/pdf...

1 Resource Group 简介 2 Resource Group 使用 2.1 创建资源组 2.2 将资源组分配给角色 2.3 修改资源组配置 2.4 删除资源组 2.5 取消资源组中的正在运行或已排队的事务 3 Resource Group 监控 3.1 查看资源组...

1 Hash Indexing 2 Page Addressing 本文为摘录，原文为： ../../../Work/pg_master/src/backend/access/hash/README 1 Hash Indexing 这个目录包含了 Postgres 的散列索引实现。其中大部分核心思想来自于 Margo Seltzer 和 Ozan Yigit 在 1991 年 1 月举行的冬季 USENIX 会议上的论文...

1 Basic Log Viewing 2 Journal Filtering by Time 2.1 Displaying Logs from the Current Boot 2.2 Filtering by Message Interest 本文为摘录，原文为： https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs 1 Basic Log Viewing 要查看 journald 守护程序收集的日志，请使用 journalctl 命令。 当单独使用时，系统中的每个...

1 ABSTRACT 2 INTRODUCTION 本文为摘录，原文为： attachments/pdf/e/p1092-loghin.pdf 1 ABSTRACT Abbrs: CFT: crash fault-tolerant BFT: byzantine fault-tolerant Byzantine Fault Tolerance (BFT) is a trait of decentralized, permissionless systems which are capable of successfully identifying and rejecting dishonest or faulty information. Byzantine fault tolerant systems have successfully solved the Byzantine Generals Problem and are robust against sybil attacks. 2 INTRODUCTION 学术界出...

1 表现 2 原因 3 绕过方法 1 表现 通过 Calibre 向 iReader 中传输书籍失败，报 MTP 相关错误。 2 原因 不知道为什么，无法在设备存储空间中创建目录 3 绕过方法 用文件管理器提...

1 The Linux Process States 1.1 Running or Runnable State (R) 1.2 Sleeping State: Interruptible (S) and Uninterruptible (D) 1.3 Stopped State (T) 1.4 Zombie State (Z) 2 Checking Process State 2.1 Displaying Process State Using ps 2.2 Using the top Command 2.3 The /proc Pseudo File 3 Summary 本文为摘录，原文为： https://www.baeldung.com/linux/process-states 1 The Linux Process States Running or Runnable (R) Uninterruptible...

1 ABSTRACT 本文为摘录，原文为： attachments/pdf/4/p1011-jin.pdf 1 ABSTRACT

1 ABSTRACT 2 INTRODUCTION 本文为摘录，原文为： attachments/pdf/8/p3548-yan.pdf 1 ABSTRACT 下一代向量数据库应该有的特性： 可长期演进 tunable consistency good elasticity high performance Manu 通过放宽数据模型和一致性约束来换取上述特性： 使用 WAL 和...

本文为摘录，原文为： attachments/pdf/a/p1187-zhang.pdf PM stands for Persistent Memory， 持久内存，它是一种非易失性内存，即使断电也能保留数据。 eADR 保证了 CPU 缓存中的数据在电源故障时会被刷新...

1 INTRODUCTION 本文为摘录，原文为： attachments/pdf/4/p1924-bhattacharya.pdf FPR: Fault Positive Rate Partitioned Bloom Filter , 方法 将 BloomFilter 划分成 segments 每个 segment 使用简单的、基于投影的哈希函数， 函数通过数据计算得来 效果 减少误报 （两个数量级...

1 Introduction 2 DESIGN OVERVIEW 2.1 Goals 2.2 Criteria of Design 3 架构图 3.1 Application Layer 3.2 Proxy Layer 3.3 Data Service Layer 3.4 Zones 3.5 表 3.6 Node 3.7 SQL Engine 3.8 Multi-tenancy 3.9 Resource Isolation. 3.10 Features 4 STORAGE ENGINE 4.1 LSM Tree-Based Architecture 4.2 Asymmetric Read and Write 4.3 Daily Incremental Major Compaction 4.4 Replica Type 5 TRANSACTION PROCESSING ENGINE 5.1 Partition and Paxos Group...

1 ABSTRACT 2 INTRODUCTION 3 PIPELINE OVERVIEW 3.1 notation 3.2 better cache utilization, 3.3 4 Phases 本文为摘录，原文为： attachments/pdf/c/p259-arman.pdf 1 ABSTRACT Mergesort 优点： 不受数据倾斜影响 适于通过向量化执行来进行并行处理 适于多线程操作操作 Origami: 内存归...

1 INTRODUCTION 2 NETWORK PROCESSING IN THE LINUX KERNEL 2.1 Kernel Accounting 2.2 Packet Transmission 发送 2.3 Packet Reception 接收 2.4 Incorrect SoftIRQ Accounting 3 TESTBED AND KERNEL CONFIGURATION 4 UDP TRANSMISSION 5 TCP TRANSMISSION 6 TCP TRANSMISSION WITH ZERO-COPY 7 THE HARDWARE OFFLOAD FUNCTIONALITIES OF THE NETWORK ADAPTER 8 FIBRE CHANNEL TO 10 GIGABIT ETHERNET TESTS 9 CONCLUSIONS 本文为摘录，原文为...

1 #9: Optimizations past their prime 1.1 Best practices 1.2 #21: Improving the efficiency of your regular expressions 本文为摘录，原文为： https://abseil.io/fast 1 #9: Optimizations past their prime 1.1 Best practices – 可能的情况下编写清晰、惯用的代码 Prefer writing clear, idiomatic code whenever possible. It is not only easier to read and...

1 Introduction 2 Why pgAudit 3 Usage Considerations 4 Settings 4.1 pgaudit.log 4.2 pgaudit.log_catalog 5 Session Audit Logging 6 Object Audit Logging 7 Format 本文为摘录，原文为： https://github.com/pgaudit/pgaudit#readme 1 Introduction PostgreSQL 审计扩展（pgAudit）通过标准的 PostgreSQL 日志记录功能提供详细的会话...