I would like to compare pipelineDB and PostgreSQL.
Reading the documentation, I found out that pipelineDB is the extension of PostgreSQL.
Then I'm getting curious : What am I have to do with PostgreSQL to compare pipelineDB?
Does system regards Postgres as pipelineDB?
Or, is there any option to switch Postgres and Pipeline extension?
There will be happen nothing. You will use Pipeline functionality via new special functions and database objects. It is great on extensions, so after installing you can use PostgreSQL as usual, and if you want, you can use special functions provided by extension.
Streams are implemented as foreign tables supported Pipelinedb - so this extension has full control over inserting, reading data to/from this object.