docs(metadata): clarify table catalog semantics

Signed-off-by: Vu Anh Phung <vu.phung@databricks.com>

Author: vuanhphung

src/databricks/sql/backend/databricks_client.py

@@ -292,9 +292,9 @@ def get_tables(
             max_rows: Maximum number of rows to fetch in a single batch
             max_bytes: Maximum number of bytes to fetch in a single batch
             cursor: The cursor object that will handle the results
-            catalog_name: Optional catalog name pattern to filter by
-                if catalog_name is None, we fetch across all catalogs; an empty
-                string matches nothing
+            catalog_name: Optional exact catalog name. ``None`` leaves the
+                filter unset; ``%`` and ``*`` select all catalogs; an empty
+                string is preserved.
             schema_name: Optional schema name pattern to filter by
                 if schema_name is None, we fetch across all schemas; an empty
                 string matches nothing

src/databricks/sql/client.py

@@ -1668,8 +1668,9 @@ def tables(
         """
         Get tables corresponding to the catalog_name, schema_name and table_name.
 
-        Empty strings are preserved; ``None`` leaves a filter unset. Names are
-        patterns, can contain % wildcards, and empty patterns match nothing.
+        Empty strings are preserved; ``None`` leaves a filter unset.
+        ``catalog_name`` is exact except that % and * select all catalogs.
+        ``schema_name`` and ``table_name`` are patterns; empty patterns match nothing.
         :returns self
         """
         self._check_not_closed()