Troubleshooting and FAQ
=======================

"No access to catalog" or "Access Denied"
-----------------------------------------

Your team does not have access to that catalog or table yet, or only to part
of the tree. The message ``No access to catalog 'x' (or it doesn't exist)``
can also mean that the name is wrong. Find the item in the **Catalog** and
request access, see :doc:`data-engineer`.

Spark says the table does not exist
-----------------------------------

Use the full three-part name ``catalog.schema.table``. Without a catalog
Spark looks in ``main``. If the name is right, you may not have access:
check in the **Catalog**.

"Unity Catalog does not support non-Delta managed table"
--------------------------------------------------------

You created a table without a format and Spark chose Parquet. Tables in the
catalog must be Delta tables. Add ``.format("delta")`` to the write:
``df.write.format("delta").saveAsTable("catalog.schema.table")``. With
``mode("overwrite")`` the same mistake shows as ``location should either be
user specified or system generated``.

A new catalog or schema is not visible in my notebook
-----------------------------------------------------

A running kernel only knows what existed when it started. Restart the kernel
(**Kernel** > **Restart Kernel**).

I cannot write to a table
-------------------------

Writing needs the role **writer** or **owner** on the table (or higher up in
the tree). A team with a filtered role can only read. Ask the owner of the
product for the role you need, see :doc:`data-engineer`.

SQL Server Management Studio cannot connect
-------------------------------------------

SSMS and Azure Data Studio only connect to Microsoft SQL Server; the
platform's SQL endpoint is Trino. A Trino ODBC driver does not help: SSMS
cannot use other drivers. A SQL Server *linked server* to Trino would reach
it, but then every query runs as one shared account instead of as you, so
your own access rules no longer apply; the platform does not support that.
Use a client with a Trino driver such as DBeaver, see :doc:`notebooks`.

I see no catalogs on the Trino web page
---------------------------------------

The Trino web page only shows running and finished queries. To browse
catalogs, schemas and tables, connect a SQL client such as DBeaver, or use
the **Catalog** in Security Center.

The message "Your Trino token has expired"
------------------------------------------

The access token of your session ran out. Sign out of JupyterHub and sign in
again, or restart your server.

My notebook server does not start
---------------------------------

If JupyterHub says it is at capacity, too many servers run at the same time:
try again in a few minutes. The first start of a new account takes a few
minutes. If it still does not start, ask your administrator.

I lost my password
------------------

There is no "forgot password" function. Ask the platform administrator of
your organization to set a new temporary password for you.

Where do I ask for help?
------------------------

Ask the owner of the data product for access questions, your platform
administrator for account and team questions, and the platform support
contact of your organization for everything else.