Postgres: Live Query Subscriptions
A Live query subscription will return the latest result of the query being made and not necessarily all the individual events leading up to the result, such as with a streaming subscription.
By default, updates are delivered to clients every 1 sec.
A live query is a query that is continuously monitored for changes in the database and automatically updates the query result whenever the underlying data changes. Live queries are a PostgreSQL-specific implementation that allow real-time updates to clients without the need for manual polling or refreshing.
Convert a query to a subscription
You can turn any query into a subscription by simply replacing
subscription as the operation type.
Hasura follows the GraphQL spec which allows for only one root field in a subscription. You also cannot execute multiple separate subscriptions in one query. To have multiple subscriptions running at the same time they must be in separate queries.