Greenplum Database 5.x Pre-Migration Actions 467 Step 2: Migrating PXF to Greenplum 6.x 468 Migrating gphdfs External Tables to PXF 470 Preparing for the Migration 471 Setting Up PXF 472 Creating a PXF External Options 475 Example gphdfs to pxf External Table Mapping for an HDFS Text File 475 Verifying Access with PXF 476 Removing the gphdfs External Tables 476 Revoking Privileges to the gphdfs Protocol 476 VMware VMware Greenplum 6 Documentation VMware, Inc 248 Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

Greenplum Database 5.x Pre-Migration Actions 462 Step 2: Migrating PXF to Greenplum 6.x 462 Migrating gphdfs External Tables to PXF 465 VMware Greenplum 6 Documentation VMware by Broadcom 22 Preparing for Options 469 Example gphdfs to pxf External Table Mapping for an HDFS Text File 470 Verifying Access with PXF 470 Removing the gphdfs External Tables 470 Revoking Privileges to the gphdfs Protocol 470 Upgrading Greenplum 6 Documentation VMware by Broadcom 280 Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

Greenplum Database 5.x Pre-Migration Actions 378 Step 2: Migrating PXF to Greenplum 6.x 379 Migrating gphdfs External Tables to PXF 381 Preparing for the Migration 381 Setting Up PXF 382 VMware Tanzu Greenplum Options 385 Example gphdfs to pxf External Table Mapping for an HDFS Text File 385 Verifying Access with PXF 386 Removing the gphdfs External Tables 386 Revoking Privileges to the gphdfs Protocol 386 Upgrading memory within the file system cache for backup. Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

Greenplum Database 5.x Pre-Migration Actions 443 Step 2: Migrating PXF to Greenplum 6.x 443 Migrating gphdfs External Tables to PXF 446 Preparing for the Migration 447 Setting Up PXF 447 Creating a PXF External Options 450 Example gphdfs to pxf External Table Mapping for an HDFS Text File 451 Verifying Access with PXF 451 Removing the gphdfs External Tables 451 Revoking Privileges to the gphdfs Protocol 451 Upgrading memory within the file system cache for backup. Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

Greenplum Database 5.x Pre-Migration Actions 451 Step 2: Migrating PXF to Greenplum 6.x 452 Migrating gphdfs External Tables to PXF 454 Preparing for the Migration 455 Setting Up PXF 456 Creating a PXF External Options 459 Example gphdfs to pxf External Table Mapping for an HDFS Text File 459 Verifying Access with PXF 460 Removing the gphdfs External Tables 460 Revoking Privileges to the gphdfs Protocol 460 Upgrading memory within the file system cache for backup. Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

Greenplum Database 5.x Pre-Migration Actions 449 Step 2: Migrating PXF to Greenplum 6.x 449 Migrating gphdfs External Tables to PXF 451 Preparing for the Migration 452 Setting Up PXF 453 Creating a PXF External Options 456 Example gphdfs to pxf External Table Mapping for an HDFS Text File 456 Verifying Access with PXF 457 Removing the gphdfs External Tables 457 Revoking Privileges to the gphdfs Protocol 457 Upgrading memory within the file system cache for backup. Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework

集群配合运作的案例越 来越多。在中国移动的大数据架 构规范中，云化 ETL 是一个重 要的组成部分。云化 ETL 就是构架在 Hadoop 集群之上。Greenplum 提供了专用产品模块 gphdfs，Greenplum 通过 gphdfs 可以直接与 HDFS 上的数据进行交互，并且可以同时发挥 Greenplum 和 Hadoop 两者并行处理的优势。 Big Date2.indd 30 16-11-22

storage for online archiving Upcoming Roadmap • S3 Writable External Tables • Certification of GPHDFS with latest Cloudera, MapR, Hortonworks • Porting PostgreSQL Foreign Data Wrappers to GPDB (longer

memory within the file system cache for backup. Pivotal Greenplum Database 6 no longer supports the gphdfs external table protocol to access a Hadoop system. Use the Greenplum Platform Extension Framework migration: If you are using the gphdfs external table protocol to access data stored in Hadoop in your Greenplum Database 5.x installation, you must first migrate your gphdfs VMware Tanzu Greenplum v6.20 external tables to use PXF instead, since Greenplum Database version 6 removes support for the gphdfs protocol. PXF actions are required if you choose a gpupgrade-based Greenplum Database 5.x to 6

来操作，编者想说，学会 读文档和看HELP真的很重要，编者能做的是，帮助各位入门和理解，但做不到详 细教学所有知识点。在6版本之前，访问Hadoop文件的主要方式是gphdfs协议， 在6版本才正式切换为PXF协议，实际上gphdfs的配置和调试更加的麻烦。 Greenplum Database 管理员指南 V6.2.1 版权所有：Esena(陈淼 +86 18616691889) 编写：陈淼 配新的版本。  如果是从5版本升级到6版本，且在5版本中配置了PXF，则需要根据PXF的升级说 明来完成PXF的升级。  在GP6中，不再支持gphdfs协议的外部表，所以，如果在之前的版本使用了gphdfs 协议的外部表，那么，在升级到6版本时，需要删除这些外部表，然后使用PXF协 议来重新创建相应的外部表。  4.3版本、5版本、6版本之间，系统表以及系统表的字段有了很多变化。所以，在