7501365 2 | 7499978 3 | 7497731 (4 rows) 支持运行长度编码 GP已支持COLUMN级别的运行长度编码(Run-length Encoding /RLE)压缩算 Greenplum Database 管理员指南 V6.2.1 版权所有：Esena(陈淼 +86 18616691889) 名称 解释 可选值 COMPRESSTYPE 使用的压缩类型 ZSTD(最好的压缩选择) ZLIB(更高压缩) QUICKLZ(更快压缩) RLE_TYPE(运行长度编码) none(无压缩、缺省值) COMPRESSLEVEL 压缩级别 ZSTD 为 1~19 级可选 ZLIB 为 1~9 级可选 QUICKLZ 仅 1 个级别可选(缺省不需指定) ext_table; =# INSERT INTO table SELECT * FROM ext_table;  WEB型的外部表提供了更灵活的数据访问方式，可以通过访问http协议的URL来获 取动态数据，或者通过执行GP集群内主机上的Linux脚本或命令来获取数据。编 者编写的gpdbtransfer命令，就是通过这种外部表来实现GP集群之间的并行数 据传输的，实现了灵活丰富的功能

获取SQL命令的帮助 \? 获取psql命令的帮助 \q 退出 2. ⼀般选项 \c [数据库名]－[⽤⼾名] 连接到新数据库 \cd [⽬录名] 改变当前的⼯作⽬录 \encoding [编码] 显⽰或设置客⼾端编码 \h [名字] SQL命令的语法帮助 \set [名字 ［值］] 设置内部变量 \timing 查询计时开关切换（默认关闭） \unset 名字 取消（删除）内部变量 3. 查询缓冲区选项 [模式] (加 "+" 获取更多信息) 列出表/索引/序列/视图/系统表 \da [模式] 列出聚集函数 \db [模式] 列出表空间 (加 "+" 获取更多的信息) \dc [模式] 列出编码转换 \dC 列出类型转换 \dd [模式] 显⽰⽬标的注释 \df [模式] 列出函数 (加 "+" 获取更多的信息) \dg [模式] 列出组 \dn [模式] 列出模式 (加 CREATE DATABASE 数据库名称 [ [ WITH ] [ OWNER [=] 数据库属主 ] [ TEMPLATE [=] 模板 ] [ ENCODING [=] 编码 ] [ TABLESPACE [=] 表空间 ] ] 命令: CREATE FUNCTION 描述: 定义⼀个新的函数 语法: CREATE [ OR REPLACE ] FUNCTION

可指定条件筛选数据进行备份  单个失败不影响整个备份任务  可增量备份-识别AO的方式与gpcrondump一致，同时支持heap表的增备(是否发生过变化)  可指定并发数(同时多张表备份)，可指定编码Encoding  乐观锁设计——单表尝试加锁失败即认为该表本次备份失败  命令简单易用——单命令无需部署，参数基本保持与gpcrondump一致，自劢完成全部必要的准备工作  恢 条件源端过滤，降低带条件场景的网络压力  源端可以是视图，自劢识别是否使用快速模式  命令可部署在可在集群外执行  自劢识别低速模式，快速模式和全速模式  可指定并发数(同时多张表传输)，可指定编码Encoding，解决特殊的乱码问题  命令简单易用——单命令无需部署，参数基本保持与gptransfer一致，自劢完成全部必要的准备工作

Protocol 0 Configuring the s3 Protocol 792 Using s3 External Tables 793 About the s3 Protocol LOCATION URL 794 About Reading and Writing S3 Data Files 795 s3 Protocol AWS Server-Side Encryption Support 796 External Web Tables 804 Creating and Using External Web Tables 0 Command-based External Web Tables 804 URL-based External Web Tables 805 Examples for Creating External Tables 805 Examples for Creating External can use this option in the CREATE EXTERNAL TABLE LOCATION clause to specify the http/https server URL from which Greenplum Database obtains the s3 protocol configuration file. gpload adds a NEWLINE property

781 Configuring the s3 Protocol 782 Using s3 External Tables 782 About the s3 Protocol LOCATION URL 783 About Reading and Writing S3 Data Files 785 s3 Protocol AWS Server-Side Encryption Support 786 Table Data 792 Creating and Using External Web Tables 793 Command-based External Web Tables 793 URL-based External Web Tables 794 Examples for Creating External Tables 794 Example 1—Single gpfdist can use this option in the CREATE EXTERNAL TABLE LOCATION clause to specify the http/https server URL from which Greenplum Database obtains the s3 protocol configuration file. gpload adds a NEWLINE property

Protocol 783 s3:// Protocol 0 Configuring and Using S3 External Tables 783 About the S3 Protocol URL 785 About S3 Data Files 786 s3 Protocol AWS Server-Side Encryption Support 787 s3 Protocol Proxy External Web Tables 795 Creating and Using External Web Tables 0 Command-based External Web Tables 795 URL-based External Web Tables 796 Examples for Creating External Tables 796 Examples for Creating External Science Library Package. 1. For an R package, identify all dependent R packages and each package web URL. The information can be found by selecting the given package from the following navigation page:

Protocol 715 s3:// Protocol 0 Configuring and Using S3 External Tables 715 About the S3 Protocol URL 717 About S3 Data Files 718 s3 Protocol AWS Server-Side Encryption Support 719 s3 Protocol Proxy External Web Tables 727 Creating and Using External Web Tables 0 Command-based External Web Tables 727 URL-based External Web Tables 728 Examples for Creating External Tables 728 Examples for Creating External Science Library Package. 1. For an R package, identify all dependent R packages and each package web URL. The information can be found by selecting the given package from the following navigation page:

621 Configuring the s3 Protocol 622 Using s3 External Tables 623 About the s3 Protocol LOCATION URL 624 About Reading and Writing S3 Data Files 626 s3 Protocol AWS Server-Side Encryption Support 626 Table Data 634 Creating and Using External Web Tables 634 Command-based External Web Tables 635 URL-based External Web Tables 635 Examples for Creating External Tables 636 Example 1—Single gpfdist can use this option in the CREATE EXTERNAL TABLE LOCATION clause to specify the http/https server URL from which Greenplum Database obtains the s3 protocol configuration file. gpload adds a NEWLINE property

505 Configuring the s3 Protocol 506 Using s3 External Tables 506 About the s3 Protocol LOCATION URL 507 About Reading and Writing S3 Data Files 509 s3 Protocol AWS Server-Side Encryption Support 509 Table Data 516 Creating and Using External Web Tables 516 Command-based External Web Tables 516 URL-based External Web Tables 517 Examples for Creating External Tables 517 Example 1—Single gpfdist can use this option in the CREATE EXTERNAL TABLE LOCATION clause to specify the http/https server URL from which Greenplum Database obtains the s3 protocol configuration file. gpload adds a NEWLINE property

615 Configuring the s3 Protocol 616 Using s3 External Tables 616 About the s3 Protocol LOCATION URL 618 About Reading and Writing S3 Data Files 619 s3 Protocol AWS Server-Side Encryption Support 620 Table Data 628 Creating and Using External Web Tables 628 Command-based External Web Tables 628 URL-based External Web Tables 629 Examples for Creating External Tables 629 Example 1—Single gpfdist can use this option in the CREATE EXTERNAL TABLE LOCATION clause to specify the http/https server URL from which Greenplum Database obtains the s3 protocol configuration file. gpload adds a NEWLINE property