Most database Connections use polling to regularly fetch data on a user specified timer. Alternatively you can create a subscription. This means the data source will push updates rather than polling. It can be more efficient for frequently updating data.

Currently to create a subscription you should:

  1. Create a "Kdb Streaming" connection type.
  2. Specify that connection as a source and set the query. e.g. .u.sub[`tblname;::]

Behind the scenes, for every unique subscription including query the server will:

  1. Open a connection to the streaming data source.
  2. Send the subscription query.
  3. Await incoming data and forward results to the dashboard. For kdb the result format is expected to be (`.u.upd;`tableName;tableData).
  4. Keep the connection open until the dashboard is closed.

Basic example kdb code to create a subscription:

Kdb+ Subscription Tutorial