feat(pinot-driver): Add enableNullHandling=true to query options

Author: igorlukanin

docs/pages/product/configuration/data-sources/pinot.mdx

@@ -14,8 +14,9 @@ workloads. [StarTree][link-startree] is a fully-managed platform for Pinot.
 - The hostname for the [Pinot][pinot] broker
 - The port for the [Pinot][pinot] broker
 
-With the current implementation of the Pinot driver, you have to enable the
-[multi-stage query engine][link-pinot-msqe] in your Pinot cluster.
+Note that the following features should be enabled in your Pinot cluster:
+- [Multi-stage query engine][link-pinot-msqe].
+- [Advanced null value support][link-pinot-nvs].
 
 ## Setup
 
@@ -97,6 +98,7 @@ Cube does not require any additional configuration to enable SSL as Pinot connec
 [link-pinot]: https://pinot.apache.org/
 [pinot]: https://docs.pinot.apache.org/
 [link-pinot-msqe]: https://docs.pinot.apache.org/reference/multi-stage-engine
+[link-pinot-nvs]: https://docs.pinot.apache.org/developers/advanced/null-value-support#advanced-null-handling-support
 [pinot-docs-approx-agg-fns]:
   https://docs.pinot.apache.org/users/user-guide-query/query-syntax/how-to-handle-unique-counting
 [ref-recipe-enable-ssl]:

packages/cubejs-pinot-driver/src/PinotDriver.ts

@@ -167,7 +167,7 @@ export class PinotDriver extends BaseDriver implements DriverInterface {
       }),
       body: JSON.stringify({
         sql: query,
-        queryOptions: `useMultistageEngine=true;timeoutMs=${this.config.queryTimeout}`
+        queryOptions: `useMultistageEngine=true;enableNullHandling=true;timeoutMs=${this.config.queryTimeout}`
       })
     });