In the prior example, we used a topic view to adapt existing topics into more intuitively named topics. In this example we will change another characteristic of the source topics: the topic properties.
Using the Topics tab we can see that topics under Demos/Fx/raw
are uncompressed: they carry the property COMPRESSION
which is set to false
, where the default is true
. Consequently, any topic subscribers will receive uncompressed updates which may consume more bandwidth and affect overall performance.
Demos/Fx currency pairs
.map ?Demos/Fx/raw/.* to Demos/Fx/<scalar(/pairName)> with properties "COMPRESSION":"true"
– notice the quotes around the key and value you are setting.Demos/Fx
.COMPRESSION
property that its source topic carries. Topics are compressed by default, so we would not expect to see the property COMPRESSION
set to true
.Summary: The topic property mapping clause with properties
can be used to set some (though not all) of the properties on the resulting reference topic.
That concludes this tutorial series on topic views.
To learn more about the full power of topic views, see the latest topic views documentation in the Diffusion manual.
For specifics of how to create topic views from your preferred Diffusion SDK, see the API documentation for the language you’re using.