fixes tests, adds docs

dlt/destinations/impl/bigquery/bigquery.py

@@ -401,10 +401,7 @@ def _get_info_schema_columns_query(
         return query, folded_table_names
 
     def _get_column_def_sql(self, column: TColumnSchema, table: PreparedTableSchema = None) -> str:
-        name = self.sql_client.escape_column_name(column["name"])
-        column_def_sql = (
-            f"{name} {self.type_mapper.to_destination_type(column, table)} {self._gen_not_null(column.get('nullable', True))}"
-        )
+        column_def_sql = super()._get_column_def_sql(column, table)
         if column.get(ROUND_HALF_EVEN_HINT, False):
             column_def_sql += " OPTIONS (rounding_mode='ROUND_HALF_EVEN')"
         if column.get(ROUND_HALF_AWAY_FROM_ZERO_HINT, False):

dlt/destinations/impl/clickhouse/clickhouse.py

@@ -292,11 +292,10 @@ def _get_table_update_sql(
 
         return sql
 
-    @staticmethod
-    def _gen_not_null(v: bool) -> str:
+    def _gen_not_null(self, v: bool) -> str:
         # ClickHouse fields are not nullable by default.
         # We use the `Nullable` modifier instead of NULL / NOT NULL modifiers to cater for ALTER statement.
-        pass
+        return ""
 
     def _from_db_type(
         self, ch_t: str, precision: Optional[int], scale: Optional[int]

dlt/destinations/job_client_impl.py

@@ -635,8 +635,7 @@ def _get_column_hints_sql(self, c: TColumnSchema) -> str:
             if c.get(h, False) is True  # use ColumnPropInfos to get default value
         )
 
-    @staticmethod
-    def _gen_not_null(nullable: bool) -> str:
+    def _gen_not_null(self, nullable: bool) -> str:
         return "NOT NULL" if not nullable else ""
 
     def _create_table_update(

docs/website/docs/dlt-ecosystem/destinations/snowflake.md

@@ -200,6 +200,12 @@ Note that we ignore missing columns `ERROR_ON_COLUMN_COUNT_MISMATCH = FALSE` and
 ## Supported column hints
 Snowflake supports the following [column hints](../../general-usage/schema#tables-and-columns):
 * `cluster` - Creates a cluster column(s). Many columns per table are supported and only when a new table is created.
+* `unique` - Creates UNIQUE hint on a Snowflake column, can be added to many columns. ([optional](#additional-destination-options))
+* `primary_key` - Creates PRIMARY KEY on selected column(s), may be compound. ([optional](#additional-destination-options))
+
+`unique` and `primary_key` are not enforced and `dlt` does not instruct Snowflake to `RELY` on them when
+query planning.
+
 
 ## Table and column identifiers
 Snowflake supports both case-sensitive and case-insensitive identifiers. All unquoted and uppercase identifiers resolve case-insensitively in SQL statements. Case-insensitive [naming conventions](../../general-usage/naming-convention.md#case-sensitive-and-insensitive-destinations) like the default **snake_case** will generate case-insensitive identifiers. Case-sensitive (like **sql_cs_v1**) will generate
@@ -308,13 +314,16 @@ pipeline = dlt.pipeline(
 ## Additional destination options
 
 You can define your own stage to PUT files and disable the removal of the staged files after loading.
+You can also opt-in to [create indexes](#supported-column-hints).
 
 ```toml
 [destination.snowflake]
 # Use an existing named stage instead of the default. Default uses the implicit table stage per table
 stage_name="DLT_STAGE"
 # Whether to keep or delete the staged files after COPY INTO succeeds
 keep_staged_files=true
+# Add UNIQUE and PRIMARY KEY hints to tables
+create_indexes=true
 ```
 
 ### Setting up CSV format

tests/load/dremio/test_dremio_client.py

@@ -48,12 +48,12 @@ def test_dremio_factory() -> None:
             [
                 TColumnSchema(name="foo", data_type="text", partition=True),
                 TColumnSchema(name="bar", data_type="bigint", sort=True),
-                TColumnSchema(name="baz", data_type="double"),
+                TColumnSchema(name="baz", data_type="double", nullable=False),
             ],
             False,
             [
                 'CREATE TABLE "test_database"."test_dataset"."event_test_table"'
-                ' (\n"foo" VARCHAR ,\n"bar" BIGINT ,\n"baz" DOUBLE )\nPARTITION BY'
+                ' (\n"foo" VARCHAR  ,\n"bar" BIGINT  ,\n"baz" DOUBLE  NOT NULL)\nPARTITION BY'
                 ' ("foo")\nLOCALSORT BY ("bar")'
             ],
         ),
@@ -66,7 +66,7 @@ def test_dremio_factory() -> None:
             False,
             [
                 'CREATE TABLE "test_database"."test_dataset"."event_test_table"'
-                ' (\n"foo" VARCHAR ,\n"bar" BIGINT ,\n"baz" DOUBLE )\nPARTITION BY'
+                ' (\n"foo" VARCHAR  ,\n"bar" BIGINT  ,\n"baz" DOUBLE  )\nPARTITION BY'
                 ' ("foo","bar")'
             ],
         ),
@@ -79,7 +79,7 @@ def test_dremio_factory() -> None:
             False,
             [
                 'CREATE TABLE "test_database"."test_dataset"."event_test_table"'
-                ' (\n"foo" VARCHAR ,\n"bar" BIGINT ,\n"baz" DOUBLE )'
+                ' (\n"foo" VARCHAR  ,\n"bar" BIGINT  ,\n"baz" DOUBLE  )'
             ],
         ),
     ],