@kapa.ai parent stream is not incremental can substream still can be incremental or not

Yes, a substream can be incremental even if the parent stream is not. However, if the parent stream is set to full refresh and the child stream is incremental, the child stream will run a full refresh of the parent stream. This is because the

HttpSubStream

calls the parent stream with

SyncMode.full_refresh

[source](https://discuss.airbyte.io/t/587). If you want both the parent and child stream to be incremental, they should share the same cursor field and you need to define your own

stream_slices

method on the child stream, reading the parent stream with

SyncMode.incremental

[source](https://discuss.airbyte.io/t/587). For nested streams, you can use a

SubstreamPartitionRouter

to implement them. The default state format is per partition, but there are options to enhance efficiency depending on your use case:

incremental_dependency

and

global_substream_cursor

[source](https://docs.airbyte.com/connector-development/config-based/understanding-the-yaml-file/incremental-syncs#nested-streams).