Serverless SQL Database - Update connection-errors.mdx (#3761)

* Update connection-errors.mdx

Add documentation on several unsupported features from Serverless SQL Database leading to errors when performed.

* Apply suggestions from code review

---------

Co-authored-by: SamyOubouaziz <[email protected]>

Author: fpagny

serverless/sql-databases/troubleshooting/connection-errors.mdx

@@ -52,6 +52,61 @@ The [IAM principal](/identity-and-access-management/iam/concepts/#principal) (us
   - `ServerlessSQLDatabaseReadWrite`
   - `ServerlessSQLDatabaseFullAccess`
 
+## ERROR: permission denied to create temporary tables/subscription in database
+
+### Problem
+
+The error messages below appear when trying to create `TEMPORARY TABLES` or `SUBSCRIPTION` in a Serverless SQL Database:
+
+    ```
+    ERROR: permission denied to create temporary tables in database
+    ERROR: permission denied to create subscription
+    ```
+
+### Cause
+
+Serverless SQL Databases do not support `TEMPORARY TABLES` or `SUBSCRIPTION` yet. Refer to the [known differences](/serverless/sql-databases/reference-content/known-differences/#unsupported-sql-features) page for more information.
+
+### Solution
+
+If you (or a third party tool you are using, especially ETL tools such as Airbyte, Fivetran or Meltano) require `TEMPORARY TABLES`, we suggest you use a [Managed Database for PostgreSQL](https://www.scaleway.com/en/database/). `SUBSCRIPTION` is not supported by Managed Databases for PostgreSQL yet, but you can [import data with ETL tools](/managed-databases/postgresql-and-mysql/api-cli/import-data-to-managed-postgresql-databases/#import-data-from-a-file-csv-txt-etc).
+
+## ERROR: prepared transactions are disabled
+
+### Problem
+
+The error message below appears when trying to use `PREPARE TRANSACTION` in a Serverless SQL Database:
+
+    ```
+    ERROR: prepared transactions are disabled
+    ```
+
+### Cause
+
+Serverless SQL Databases do not support `PREPARE TRANSACTION`. Refer to the [dedicated documentation](/serverless/sql-databases/reference-content/known-differences/#unsupported-sql-features) for more information.
+
+### Solution
+
+If you require this feature, we suggest you use a [Managed Database for PostgreSQL](/managed-databases/postgresql-and-mysql/).
+
+## ERROR: cannot refresh materialized view concurrently
+
+### Problem
+
+The error message below appears when trying to connect to the Serverless SQL Database:
+
+    ```
+    ERROR: cannot refresh materialized view "example-view" concurrently
+    ```
+
+### Cause
+
+Serverless SQL Databases do not support `REFRESH MATERIALIZED VIEW CONCURRENTLY`. However, the `REFRESH MATERIALIZED VIEW` command is supported, only the `CONCURRENTLY` keyword is not supported. Refer to the [dedicated documentation](/serverless/sql-databases/reference-content/known-differences/#unsupported-sql-features) for more information. 
+
+### Solution
+
+If you require this feature, we suggest you use a [Managed Database for PostgreSQL](/managed-databases/postgresql-and-mysql/).
+
 ## Database hostname was not sent to server
 
 ### Problem
@@ -105,4 +160,4 @@ This error happens when the SQL client you are using does not support the TLS Se
 | N/A      | IntelliJ (SQL Module) | Yes           |                                                                                 |
 | N/A      | navicat               | No            |                                                                                 |
 | N/A      | Stitch                | No            |                                                                                 |
-| N/A      | Terraform             | No            | Terraform includes an older lib/pq version (v1.10.3) which does not support SNI. |
+| N/A      | Terraform             | No            | Terraform includes an older lib/pq version (v1.10.3) which does not support SNI. |