Improve Snowflake Iceberg catalog docs

Co-authored-by: Manfred Moser <[email protected]>

docs/src/main/sphinx/connector/iceberg.md

@@ -76,13 +76,15 @@ implementation is used:
   - Description
   - Default
 * - `iceberg.catalog.type`
-  - Define the metastore type to use. Possible values are:
+  - Define the [metastore type](general-metastore-properties) to use. Possible
+    values are:
 
     * `hive_metastore`
     * `glue`
     * `jdbc`
     * `rest`
     * `nessie`
+    * `snowflake`
   -
 * - `iceberg.file-format`
   - Define the data storage file format for Iceberg tables. Possible values are:

docs/src/main/sphinx/object-storage/metastores.md

@@ -44,7 +44,8 @@ are also available. They are discussed later in this topic.
     Iceberg connector to configures different Iceberg metadata catalogs.
 
     You must set this property in all Iceberg catalog property files. Valid
-    values are `HIVE_METASTORE`, `GLUE`, `JDBC`, `REST`, and `NESSIE`.
+    values are `hive_metastore`, `glue`, `jdbc`, `rest`, `nessie`, and
+    `snowflake`.
   -
 * - `hive.metastore-cache.cache-partitions`
   - Enable caching for partition metadata. You can disable caching to avoid
@@ -612,6 +613,21 @@ iceberg.snowflake-catalog.password=secret
 iceberg.snowflake-catalog.database=db
 ```
 
+When using the Snowflake catalog, data management tasks such as creating tables,
+must be performed in Snowflake because using the catalog from external systems
+like Trino only supports `SELECT` queries and other [read operations](sql-read-operations).
+
+Additionally, the [Snowflake-created Iceberg
+tables](https://docs.snowflake.com/en/sql-reference/sql/create-iceberg-table-snowflake)
+do not expose partitioning information, which prevents efficient parallel reads
+and therefore can have significant negative performance implications.
+
+The Snowflake catalog does not support [view management](sql-view-management) or
+[materialized view management](sql-materialized-view-management).
+
+Further information is available in the [Snowflake catalog
+documentation](https://docs.snowflake.com/en/user-guide/tables-iceberg-catalog).
+
 (partition-projection)=
 ## Access tables with Athena partition projection metadata