Doing a quick google on error ORA-00933 - it sounds like that shouldn't be thrown with a SELECT statement.  Is there more to the query that you did not include...

If the app is changing data and is doing it in a transaction, it could be they forgot to put a COMMIT in there.  Unlikely, but possible.

The other thing that...

From looking at it, it looks like the columnstore index is giving a bad estimate and that is causing it to use the clustered columnstore index as the estimates make...

It depends.  If the application has a timeout on the SQL connection configured, then the connection will go away when it is closed or timed out.  If the application has...

I am fairly certain those are showing the current connections to SQL Server.  You can connect to SQL Server and leave your connection idle for days and it is still...

As far as I know, SQL Server does not keep historical connection information.  You can see current information and it wouldn't be impossible to build up a snapshot system where...

First thing I notice is that your statistics look to be out of date with the cci plan.

Second, could you provide an actual execution plan for the rid method?   that...

I'd be checking your maintenance schedules.  Things like statistics updates, index rebuilds, index reorganizations, etc.  Or an absolute worst case - flushing any caches.

Since the problem happens around the same...

I personally don't use R or Python in SQL Server, but my understanding is that both of these have great analytics and graphing libraries in them.

Do you have some sample data where there are duplicates?  With the sample data you provided, the results appear identical to what you had in the screenshot.

If I know some...

Unfortunately, the only reply I see is Phil's latest one.  The one before that was flagged as SPAM.

But Phil is well known on this forum, so I doubt his reply...

As far as I know, there is no magic number to say more than x indexes will impact performance.  Having 1 index may impact performance, 2 might, or 100 might...

I agree with Thom.  I want to add another point that MIGHT be a cause for slowness - memory.  If the package is a simple data flow task that just...

Can you post the relevant logs or portions of the logs?  My expectation is that the logs will give us (and you) a better idea as to what is happening...

Looking at your tables, do you have any keys on them?  If so, then it is pretty easy to do.  If you have no keys on it, then it is...