Designating a Presto connector property as overridable in the QueryGrid portlet allows you to override configured Presto connector properties when running queries during an individual processing session.
Presto catalogs define their own properties. You can view these properties using the show session command. The following example shows the Presto session property called override in the Presto QueryGrid catalog p2p_active.
trino:default> show session; Name |Value|Default| Type | -------------------+--------------------------------------------------------- p2p_active.override| | | varchar| Properties to p2p_active.override -----------------------------------------------------------+ for QG connector. Of form [name]=[value];[name]=[value];...
- Under Fabric Configuration, select Fabrics.
- Select the fabric.
- Perform one of the following:
Option Description To override a Presto connector property in the Connectors tab - Select the Connectors tab.
- Select
next to the connector that has a property to override. - Select Edit.
- Select
next to Connector Software. - Find the Presto connector property to override and select the Overridable check box.
- Select OK.
- Select Save..
To override a Presto connector property in the Links tab - Select the Links tab.
- Select next to the link that has a property to override.
- Select Edit.
- Select next to Initiating Connector or Target Connector.
- Find the Presto link property to override and select the Overridable check box.
- Select OK.
- Select Save..
- To override the Presto connector property during a Presto session, use the syntax in the following example.
set session p2p_active.override = ‘<prop1>=<overrideVal1>;<prop2>=<overrideVal2>;…’;
For example:SET SESSION p2p_active.override='responsetimeout = 3000000;linkBufferCount=3;';
trino:default> show session; Name | Value |Default --------------------+---------------------------------------------+------- p2p_active.override| responsetimeout = 3000000;linkBufferCount=3; | | Type | +----------------------------------------------------------------------- |varchar|Properties to override for QG connector. Of form [name]=[value]; --------------- [name]=[value];
- [Optional] To clear Presto connector property overrides without closing a Presto session, use the syntax in the following example.
reset session p2p_active.override;