How is a published "hosted feature layer" stored in Portal

[BoGuo]

We understand that when publishing a hosted feature layer by following this instruction, Publish hosted feature layers—Portal for ArcGIS | Documentation for ArcGIS Enterprise ,  the data goes into "ArcGIS Data Store." 

But in the case of uploading an FDGB, is the data ended up in an RDBMS behind the scene or the data is actually stored in a folder accessible to the portal services? 

If the answer is the former, as we'd suspect, does that mean the ArcGIS Data Store includes its an RDBMS engine such as Postgresql?  We did not install any RDBMS as part of the enterprise installation, nor could we find any RDBMS services on the host machine.  So we are baffled...

Thanks!

Bo 

[JacobBoyle412 · Accepted solution]

You are correct, a Base ArcGIS Enterprise installation includes Portal, Hosted ArcGIS Server, Relational Data Store, and optionally Web Adaptor.

Relational Data Store does in-fact leverage PostgreSQL server under the hood, so to speak, but it runs under the Data Store Windows Service and you'll also see some PostgreSQL tasks running on the host machine in Task Manager.  The software manages the PostgreSQL and does not require any intervention in most cases.  In the case of your file geodatabase, the data is loaded to the Relational Data Store and served out by the hosting ArcGIS Server.  The file geodatabase itself is also stored in the Portal Content Store as it is considered a separate item.

Each of the 3 Data Store types utilizes a different engine, each was chosen based on the kind of data. 

[Kevin_MacLeod]

Since you are one of the product leaders, if I may cross-post from Updating Hosted Layer from Enterprise GDB - Esri Community 

Jacob - Does SDE sync to hosted feature layers out of the box now?  In other words does it or can it push data? We have 10.9.1, that would be wonderful. But even if it's 11.3 or coming to 11.4 or 11.5 that would be great to hear. 

In a perfect world, hosted feature layers would act just like a referenced service pointing to SDE.  Is that how it works in Enteprise 11.x?  I am guessing no?  I see a script above, to copy data. What if the schema changes?  Also I am wary of python bandaids on the Esri stack unless it's the only way.  Basically, wouldn't it be great if the hosted feature layer was an exact twin of the SDE layer? And the second data changes on SDE, it would push. Or perhaps push on a specified syncing schedule. Same thing with schema, if it changes, sync it, done. I am guessing... no. I'm not sure I see the point of hosted feature layers in this case. Vector tiles are great but it's too much work to leverage.  Frankly I wish Esri had implemented hosted feature layer functionality natively in SDE. My guess, it was too much work to support multiple RDBMSs (SQL Server, Oracle, others).  Which is understandable. But, we need some way of relying on hosted feature layers mirroring SDE.  Possible? Or, is it coming?

And sidenote, hopefully, one day vector tiles will support featureServer cabilities, ie Identify/Query. (basically both things put together in one endpoint, one service sublayer, not two different REST endpoints doubling the amount of layers in an app)

Thank you for input or guidance.

I think for now, I'm going to re-architect our current situation, where we have several databases and no versioning..   to Posting all DBs into the Default, and keep that Protected, at the top, so that I can point map viewers to this for read-only services.  Because ..... FeatureServer services require ALL layers to be from one singular database connection.  (I always wondered why that was the case, but at least as of 10.91 that seems to be required still).  One reason is so labels for all layers can be aware of each other in terms of placement.