Concept of tables in SSB
The core abstraction for Streaming SQL is a Table which represents both inputs and outputs of the queries. SQL Stream Builder tables are an extension of the tables used in Flink SQL to allow a bit more flexibility to the users.
A Table is a logical definition of the data source that includes the location and connection parameters, a schema, and any required, context specific configuration parameters. Tables can be used for both reading and writing data in most cases. You can create and manage tables either manually or they can be automatically loaded from one of the catalogs as specified using the Data Providers section.
In SELECT
queries the FROM
clause defines the table sources
which can be multiple tables at the same time in case of JOIN
or more complex
queries.
When you execute a query, the results go to the table you specify after the INSERT INTO statement in the SQL window. This allows you to create aggregations, filters, joins, and so on, and then route the results to another table. The schema for the results is the schema that you have created when you ran the query.
INSERT INTO air_traffic -- the name of the table sink
SELECT
lat,lon
FROM
airplanes -- the name of the table source
WHERE
icao <> 0;