A Hologres SQL node lets you run standard PostgreSQL queries on large-scale data in MaxCompute directly from DataWorks, without migrating your data.
Prerequisites
Before you begin, make sure you have:
A Hologres compute engine instance added on the Workspace Configurations page. For details, see Configure a workspace.
Develop and run a Hologres SQL node
Step 1: Write your SQL
Write your SQL in the editor.
To pass values dynamically at runtime, define variables using the ${variable_name} syntax, then assign values to those variables in the Schedule panel on the right. For more information, see Parameters.
SELECT col_1, col_2 FROM your_table_name WHERE pt > ${pt_num} LIMIT 500;Queries return a maximum of 200 rows by default. To display more rows, add a LIMIT clause to your SELECT statement. The maximum you can display is 10,000 rows.
Step 2: Configure and run the task
In the Run Configuration panel, select the compute engine and resource group for this task.
NoteTo access data sources over the public network or in a Virtual Private Cloud (VPC) environment, use a scheduling resource group that can connect to the data source. For details, see Network connectivity solutions.
From the Select Data Source drop-down list in the toolbar, select your Hologres data source.
Click Run.
Click Save.
Step 3: Configure scheduling
To run this node on a recurring schedule, configure its scheduling settings. For details, see Node scheduling configuration.
Step 4: Publish the node
After configuring the node, publish it to make it active. For details, see Node and workflow deployment.
Step 5: Monitor in Operation Center
After publishing, track the status of your periodic task in Operation Center. For details, see Getting started with Operation Center.