This topic describes how to create a Hologres SQL node. Hologres seamlessly integrates with MaxCompute at the underlying layer. This integration allows you to use standard PostgreSQL statements to query and analyze large amounts of data stored in MaxCompute without transferring data, enabling you to quickly obtain query results.
Prerequisites
You have attached a Hologres computing resource.
Procedure
Go to the DataStudio page.
Log on to the DataWorks console. In the top navigation bar, select the desired region. In the left-side navigation pane, choose . On the page that appears, select the desired workspace from the drop-down list and click Go to Data Development.
Create a Workflow.
If you have an existing Workflow, skip this step.
Move the pointer over the
icon and select Workflow.
In the Create Workflow dialog box, configure the Workflow Name parameter.
Click Create.
Create a Hologres SQL node.
Move the pointer over the
icon and choose .
You can also find the workflow in which you want to create a Hologres SQL node, right-click Hologres, and choose
.In the Create Node dialog box, configure the Node Name parameter.
NoteThe node name must be 1 to 128 characters in length and can contain letters, digits, underscores (_), and periods (.).
Click OK.
On the configuration tab of the node, write and run code in the code editor.
After the Hologres SQL node is created, edit the code in compliance with the Hologres SQL syntax. For more information about the Hologres SQL syntax, see SELECT.
NoteWhen you query data by using a
SELECT
syntax that does not include alimit
clause, only 200 query results are displayed by default. If you need to display more data, you can add alimit
clause after theSELECT
syntax. The maximum number of query results that can be displayed is 10,000.For example, if you execute the
select col_1,col_2 from your_table_name where pt>0 limit 500;
statement to query data, a maximum of 500 records are returned.- Click Properties on the right side of the node editing area to configure scheduling properties for the node. For more information, see Configure basic properties.
- Save and commit the node.Important You must configure the Rerun and Parent Nodes parameters before you commit the node.
- Click the
icon in the toolbar to save the node.
- Click the
icon in the toolbar.
- In the Commit Node dialog box, configure the Change Description parameter.
- Click OK.
If the workspace that you use is in standard mode, you must click Deploy in the upper-right corner after you commit the node. For more information, see Deploy nodes. - Click the
- Perform O&M operations on the node. For more information, see Perform basic O&M operations on auto triggered nodes.