Greenplum Connector

The Greenplum connector allows querying and creating tables in an external Greenplum database. This can be used to join data between different systems like Greenplum and Hive, or between two different Greenplum instances. The Greenplum connector is extended from PostgreSQL connector, and We enable query push down feature for Greenplum connector.

Configuration

The base configuration of Greenplum connector is the same as PostgreSQL connector. For example, you can mount the Greenplum connector by creating a file named greenplum.properties in configuration directory etc/catalog. And create the file with the following contents, replacing the connection properties with correct string.

connector.name=greenplum
connection-url=jdbc:postgresql://example.net:5432/database
connection-user=root
connection-password=secret

Table modification

We can set the greenplum.allow-modify-table in the greenplum.properties to allow to modify the table or not. If greenplum.allow-modify-table is set to false, you can not create/rename/add column/rename column/drop column. And greenplum.allow-modify-table is set to true by default.

greenplum.allow-modify-table=true

Enable query push down in Greenplum connector

The query push down feature help you to push filter, project or other sql operators down to the Greenplum database which can reduce data transmission volume between openLooKeng and Greenplum data source. If jdbc.pushdown-enabled is set to false, query push down is disabled. Or jdbc.pushdown-enabled is set to true, query push down is enabled. The query push down feature is turn on by default. For example, to disable query push down, you can set connection properties in the catalog file as follows:

jdbc.pushdown-enabled=false
  • Mode for the push-down feature

By default, the push-down mode of the Greenplum connector is BASE_PUSHDOWN. If you want to enable all push-down, you can also set the parameter as follows:

jdbc.pushdown-module=FULL_PUSHDOWN  
#FULL_PUSHDOWN: All push down. BASE_PUSHDOWN: Partial push down, which indicates that filter, aggregation, limit, topN and project can be pushed down.

Others

About the other configurations and how to query greenplum, You can refer to the document of PostgreSQL connector for more details.

有奖捉虫

“有虫”文档片段

0/500

存在的问题

文档存在风险与错误

● 拼写,格式,无效链接等错误;

● 技术原理、功能、规格等描述和软件不一致,存在错误;

● 原理图、架构图等存在错误;

● 版本号不匹配:文档版本或内容描述和实际软件不一致;

● 对重要数据或系统存在风险的操作,缺少安全提示;

● 排版不美观,影响阅读;

内容描述不清晰

● 描述存在歧义;

● 图形、表格、文字等晦涩难懂;

● 逻辑不清晰,该分类、分项、分步骤的没有给出;

内容获取有困难

● 很难通过搜索引擎,openLooKeng官网,相关博客找到所需内容;

示例代码有错误

● 命令、命令参数等错误;

● 命令无法执行或无法完成对应功能;

内容有缺失

● 关键步骤错误或缺失,无法指导用户完成任务,比如安装、配置、部署等;

● 逻辑不清晰,该分类、分项、分步骤的没有给出

● 图形、表格、文字等晦涩难懂

● 缺少必要的前提条件、注意事项等;

● 描述存在歧义

0/500

您对文档的总体满意度

非常不满意
非常满意

请问是什么原因让您参与到这个问题中

您的邮箱

创Issue赢奖品
根据您的反馈,会自动生成issue模板。您只需点击按钮,创建issue即可。
有奖捉虫