准备简单的数据： CREATE TABLE students ​(​id ​int​,​ name text​)​ DISTRIBUTED BY ​(​id​); CREATE TABLE classes​(​id ​int​,​ classname text​,​ student_id ​int​)​ DISTRIBUTED BY ​(​id​); INSERT INTO students VALUES VALUES ​(​1​,​ ​'​steven​'),​ ​(​2​,​ ​'​changchang​'),​ ​(​3​,​ ​'​guoguo​'); INSERT INTO classes VALUES ​(​1​,​ ​'​math​',​ ​1​),​ ​(​2​,​ ​'​math​',​ ​2​),​ ​(​3​,​ ​'​physics​',​ ​3​); 以下面的SQL为例子，了解 ​classname FROM students s​,​ classes c WHERE s​.​id​=​c​.​student_id 3.1 查询计划 其对应的查询计划如下所示： test=# explain SELECT s.name student_name, c.classname test-# FROM students s, classes c test-# WHERE s.id=c

Backing Up and Restoring a Database 300 Completing the Migration 301 Working With Hash Operator Classes in Greenplum 6 301 Enabling iptables (Optional) 303 How to Enable iptables 303 Example iptables PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles similarity of alphanumeric text based on trigram matching. The module also provides index operator classes that support fast searching for similar strings. The pageinspect module now includes support for

Backing Up and Restoring a Database 296 Completing the Migration 297 Working With Hash Operator Classes in Greenplum 6 297 Enabling iptables (Optional) 299 Enabling iptables (Optional) 0 How to Enable non-default hash operator classes, named cdbhash_*_ops. The non-default operator classes are used when upgrading from Greenplum Database earlier than 6.0. The legacy operator classes are compatible with each other, but if you mix the legacy operator classes with the new ones, queries will require Redistribute Motions. The server configuration parameter gp_use_legacy_hashops controls whether the legacy

Backing Up and Restoring a Database 305 Completing the Migration 306 Working With Hash Operator Classes in Greenplum 6 307 Enabling iptables (Optional) 308 Enabling iptables (Optional) 0 How to Enable non-default hash operator classes, named cdbhash_*_ops. The non-default operator classes are used when upgrading from Greenplum Database earlier than 6.0. The legacy operator classes are compatible with each other, but if you mix the legacy operator classes with the new ones, queries will require Redistribute Motions. The server configuration parameter gp_use_legacy_hashops controls whether the legacy

Backing Up and Restoring a Database 479 Completing the Migration 480 Working With Hash Operator Classes in Greenplum 6 480 Migrating from Open Source Greenplum Database to VMware Greenplum 482 Prerequisites join condition for a character column and returned incorrect results because it grouped operator classes belonging to different operator families as equivalent. 32770 : Resolves an issue where a query PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles

Backing Up and Restoring a Database 485 Completing the Migration 485 Working With Hash Operator Classes in Greenplum 6 486 Migrating from Open Source Greenplum Database to VMware Greenplum 487 Prerequisites join condition for a character column and returned incorrect results because it grouped operator classes belonging to different operator families as equivalent. 32770 Resolves an issue where a query PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles

Backing Up and Restoring a Database 460 Completing the Migration 461 Working With Hash Operator Classes in Greenplum 6 461 Migrating from Open Source Greenplum Database to VMware Greenplum 463 Prerequisites join condition for a character column and returned incorrect results because it grouped operator classes belonging to different operator families as equivalent. 32770 : Resolves an issue where a query PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles

Index-Only Scans and Covering Indexes 391 BRIN Indexes 394 Index Maintenance 395 Built-in Operator Classes 396 Creating and Managing Views 397 Creating Views 397 Dropping Views 397 Best Practices when community-driven open-source library of datasets deprecat Python @deprecat decorator to deprecate old python classes, functions or methods dill serialize all of python fastprogress A nested progress with plotting to expose an extensible API with enforced method signatures and consistent documentation jaraco.classes Utility functions for Python class constructs jaraco.collections Collection objects similar to those

Backing Up and Restoring a Database 468 Completing the Migration 468 Working With Hash Operator Classes in Greenplum 6 469 Enabling iptables (Optional) 470 How to Enable iptables 471 Example iptables PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles Greenplum 6 Documentation VMware, Inc 156 trigram matching. The module also provides index operator classes that support fast searching for similar strings. The pageinspect module now includes support for

Backing Up and Restoring a Database 465 Completing the Migration 466 Working With Hash Operator Classes in Greenplum 6 466 Enabling iptables (Optional) 468 How to Enable iptables 468 Example iptables PostgreSQL contrib module. This module provides sample generalized inverted index (GIN) operator classes that implement B-tree equivalent behavior for certain data types. Greenplum 6.20.0 now bundles similarity of alphanumeric text based on trigram matching. The module also provides index operator classes that support fast searching for similar strings. The pageinspect module now includes support for