Introduction to Materialized Views
SQL Stream Builder has the capability to materialize results from a Streaming SQL query to a persistent view of the data that can be read through REST. Business Intelligence tools and applications can use the Materialized View REST endpoint to query streams of data without deploying database systems.
Materialized Views are in synchronization with the mutating stream - they are updated by a primary key as data flows through the system. The data is updated by a given key, and it represents the latest view of the data by key.
For example: vehicleID Z latest latitude and longitude is X and Y. As the vehicle moves, the latitude and longitude for the vehicleID are updated . The primary key is defined at creation time and is immutable.
Materialized Views can be created as mutating snapshots of the queried data result that is updated by a given key. The data is always the latest representation of itself by key (analogous to a primary key in most RDBMS systems).
You can query the Materialized Views using a GET request over REST, which returns a JSON
"Content-Type: application/json". The queries are not defined at
query time. Rather, they are curated, saved, and granted access through the Cloudera platform.
You can configure a REST endpoint to query the Materialized View. Multiple query conditions can
be created to allow various ways to query the same data. This is sometimes referred to as a 'pull
When a key is removed from the incoming messages of a source, SSB continues to consume them.
However, it marks the missing key as
NULL at the sink. Similarly, when a key is
removed from the source schema, but not from the incoming messages of the source, SSB ignores
the key on the incoming stream.