Support chDB as a driver

.gitignore

@@ -97,3 +97,5 @@ dbt-tut
 dev/
 .python-version
 *_project/
+.user.yml
+chdb_state

CHANGELOG.md

@@ -1,3 +1,7 @@
+### Release [1.8.5], 2024-11-22
+### Improvement
+* Added an adapter for chDB in dbt-clickhouse [#369](https://github.com/ClickHouse/dbt-clickhouse/pull/369) and updated documentation for the new feature.
+
 ### Release [1.8.4], 2024-09-17
 ### Improvement
 * The S3 help macro now support a `role_arn` parameter as an alternative way to provide authentication for S3 based models.  Thanks to

README.md

@@ -68,7 +68,7 @@ your_profile_name:
       schema: [default] # ClickHouse database for dbt models
 
       # optional
-      driver: [http] # http or native.  If not set this will be autodetermined based on port setting
+      driver: [http] # http, native or chdb.  If not set this will be autodetermined based on port setting
       host: [localhost] 
       port: [8123]  # If not set, defaults to 8123, 8443, 9000, 9440 depending on the secure and driver settings 
       user: [default] # User for all database operations
@@ -92,6 +92,10 @@ your_profile_name:
       # Native (clickhouse-driver) connection settings
       sync_request_timeout: [5] # Timeout for server ping
       compress_block_size: [1048576] # Compression block size if compression is enabled
+
+      # chDB (clikchouse-driver) path settings
+      chdb_state_dir: [<empty string>] # The path where chdb will leave it's states
+      chdb_dump_dir: [<empty string>] # The path where dbt-clickhouse will find the dumps to initialise chdb
 
 ```
 

dbt/adapters/clickhouse/chdbclient.py

@@ -0,0 +1,181 @@
+import json
+from pathlib import Path
+from typing import List
+
+import pkg_resources
+from chdb import ChdbError, session
+from chdb.dbapi import converters
+from dbt_common.exceptions import DbtDatabaseError
+
+from dbt.adapters.clickhouse import ClickHouseColumn, ClickHouseCredentials
+from dbt.adapters.clickhouse.dbclient import ChClientWrapper
+from dbt.adapters.clickhouse.logger import logger
+
+try:
+    driver_version = pkg_resources.get_distribution("chdb").version
+except pkg_resources.ResolutionError:
+    driver_version = "unknown"
+
+
+class ChDBClient(ChClientWrapper):
+    def query(self, sql, **kwargs):
+        # TODO: we might need to preprocess `sql`
+        try:
+            result = self._client.query(sql, "JSON", **kwargs)
+            result = CHDBResult(result=result)
+            result.read()
+            return result
+        except CHDBResultError as ex:
+            raise DbtDatabaseError(
+                f"reading result from chdb query using json failed: {str(ex).strip()}"
+            ) from ex
+        except ChdbError as ex:
+            raise DbtDatabaseError(f"chdb query failed with exception: {str(ex).strip()}") from ex
+        except Exception as ex:
+            raise DbtDatabaseError(str(ex).strip()) from ex
+
+    def command(self, sql, **kwargs):
+        try:
+            result = self._client.query(sql, **kwargs)
+            if result.has_error():
+                raise DbtDatabaseError(str(result.error_message.strip()))
+            elif result.size() == 0:
+                return True
+            else:
+                result = int(result.data())
+            return result
+        except Exception as ex:
+            raise DbtDatabaseError(f"chdb command failed with exception: {str(ex).strip()}") from ex
+
+    def columns_in_query(self, sql: str, **kwargs) -> List[ClickHouseColumn]:
+        try:
+            query_result = self._client.query(
+                f"SELECT * FROM ( \n" f"{sql} \n" f") LIMIT 0",
+                **kwargs,
+            )
+            return [
+                ClickHouseColumn.create(name, ch_type.name)
+                for name, ch_type in zip(query_result.column_names, query_result.column_types)
+            ]
+        except ChdbError as ex:
+            raise DbtDatabaseError(
+                f"chdb columns_in_query failed with exception: {str(ex).strip()}"
+            ) from ex
+        except Exception as ex:
+            raise DbtDatabaseError(str(ex).strip()) from ex
+
+    def get_ch_setting(self, setting_name):
+        try:
+            result = self._client.query(
+                f"SELECT value, readonly FROM system.settings WHERE name = '{setting_name}'",
+                "JSON",
+            )
+            if result.has_error():
+                raise DbtDatabaseError(str(result.error_message.strip()))
+            else:
+                result = json.loads(result.data())
+                result = result["data"][0]
+                return (result["value"], int(result["readonly"])) if result else (None, 0)
+        except Exception as ex:
+            logger.warning("Unexpected error retrieving ClickHouse server setting", ex)
+            return None
+
+    def close(self):
+        pass
+        # self._client.cleanup()
+
+    def _create_client(self, credentials: ClickHouseCredentials):
+        # We want to append the path below to target_dir to have relative paths implementation in the configuration
+        chdb_state_dir = Path(credentials.chdb_state_dir)
+
+        if not chdb_state_dir.exists():
+            logger.debug(f"Provided chdb_state_dir doesn't exist: {chdb_state_dir}")
+            chdb_state_dir.mkdir(parents=True, exist_ok=True)
+
+        session_dir = chdb_state_dir / f"{self._conn_settings['session_id']}"
+        logger.info(f"Provided session_dir: {session_dir}")
+        client = session.Session(path=session_dir.as_posix())
+
+        # We want to append the path below to target_dir to have relative paths implementation in the configuration
+        chdb_dump_dir = Path.cwd() / credentials.chdb_dump_dir
+        chdb_dump_files = list(chdb_dump_dir.glob("**/*.sql"))
+        if len(chdb_dump_files) == 0:
+            logger.warning(f"Provided chdb_dump_files is empty: {chdb_dump_files}")
+            return
+
+        for chdb_dump_file in chdb_dump_files:
+            sql_content = chdb_dump_file.read_text()
+            try:
+                client.query(sql_content)
+            except ChdbError as ex:
+                raise DbtDatabaseError(
+                    f"client creation failed with exception: {str(ex).strip()}"
+                ) from ex
+        return client
+
+    def _set_client_database(self):
+        pass
+
+    def _server_version(self):
+        return self._client.query("select version()").data().strip().replace('"', "")
+
+
+class CHDBResultError(Exception):
+    pass
+
+
+# TODO: This is from https://github.com/chdb-io/chdb/blob/e326128df44248b187b4f421bf6a5c796791b2dc/chdb/dbapi/connections.py#L175C1-L217C70
+#       We might want to use the dbApi instead
+class CHDBResult:
+    def __init__(self, result):
+        """
+        :type connection: Connection
+        """
+        self.result = result
+        self.affected_rows = 0
+        self.insert_id = None
+        self.warning_count = 0
+        self.message = None
+        self.field_count = 0
+        self.description = None
+        self.rows = None
+        self.has_next = None
+        self.result_set = None
+        self.column_names = None
+
+    def read(self):
+        # Handle empty responses (for instance from CREATE TABLE)
+        if self.result is None:
+            return
+
+        if self.result.has_error():
+            raise CHDBResultError(str(self.result.error_message.strip()))
+
+        try:
+            data = json.loads(self.result.data())
+        except Exception as error:
+            raise CHDBResultError("Unexpected error when loading query result in JSON") from error
+
+        try:
+            self.field_count = len(data["meta"])
+            description = []
+            column_names = []
+            for meta in data["meta"]:
+                fields = [meta["name"], meta["type"]]
+                column_names.append(meta["name"])
+                description.append(tuple(fields))
+            self.description = tuple(description)
+            self.column_names = column_names
+            rows = []
+            for line in data["data"]:
+                row = []
+                for i in range(self.field_count):
+                    column_data = converters.convert_column_data(
+                        self.description[i][1], line[self.description[i][0]]
+                    )
+                    row.append(column_data)
+                rows.append(tuple(row))
+            self.rows = tuple(rows)
+            self.result_set = tuple(rows)
+        except Exception as error:
+            raise CHDBResultError("Read return data err") from error

dbt/adapters/clickhouse/credentials.py

@@ -36,6 +36,8 @@ class ClickHouseCredentials(Credentials):
     local_db_prefix: str = ''
     allow_automatic_deduplication: bool = False
     tcp_keepalive: Union[bool, tuple[int, int, int], list[int]] = False
+    chdb_state_dir: str = ""
+    chdb_dump_dir: str = ""
 
     @property
     def type(self):

dbt/adapters/clickhouse/dbclient.py

@@ -42,8 +42,10 @@ def get_db_client(credentials: ClickHouseCredentials):
     elif driver == 'native':
         if not port:
             port = 9440 if credentials.secure else 9000
+    elif driver == "chdb":
+        logger.debug(f"using chdb driver with {credentials}")
     else:
-        raise FailedToConnectError(f'Unrecognized ClickHouse driver {driver}')
+        raise FailedToConnectError(f"Unrecognized ClickHouse driver {driver}")
 
     credentials.driver = driver
     credentials.port = port
@@ -56,8 +58,20 @@ def get_db_client(credentials: ClickHouseCredentials):
             return ChNativeClient(credentials)
         except ImportError as ex:
             raise FailedToConnectError(
-                'Native adapter required but package clickhouse-driver is not installed'
+                "Native adapter required but package clickhouse-driver is not installed"
             ) from ex
+    elif driver == "chdb":
+        try:
+            import chdb
+
+            from dbt.adapters.clickhouse.chdbclient import ChDBClient
+
+            return ChDBClient(credentials)
+        except ImportError as ex:
+            raise FailedToConnectError(
+                "chDB adapter required but package chdb is not installed"
+            ) from ex
+
     try:
         import clickhouse_connect  # noqa
 

dbt/adapters/clickhouse/logger.py

@@ -1,3 +1,3 @@
 from dbt.adapters.events.logging import AdapterLogger
 
-logger = AdapterLogger('dbt_clickhouse')
+logger = AdapterLogger("dbt_clickhouse")

dbt/adapters/clickhouse/nativeclient.py

@@ -12,9 +12,9 @@
 from dbt.adapters.clickhouse.logger import logger
 
 try:
-    driver_version = pkg_resources.get_distribution('clickhouse-driver').version
+    driver_version = pkg_resources.get_distribution("clickhouse-driver").version
 except pkg_resources.ResolutionError:
-    driver_version = 'unknown'
+    driver_version = "unknown"
 
 
 class ChNativeClient(ChClientWrapper):
@@ -48,7 +48,7 @@ def get_ch_setting(self, setting_name):
                 f"SELECT value, readonly FROM system.settings WHERE name = '{setting_name}'"
             )
         except clickhouse_driver.errors.Error as ex:
-            logger.warn('Unexpected error retrieving ClickHouse server setting', ex)
+            logger.warning("Unexpected error retrieving ClickHouse server setting", ex)
             return None
         return (result[0][0], result[0][1]) if result else (None, 0)
 
@@ -88,7 +88,7 @@ def _set_client_database(self):
     def _server_version(self):
         server_info = self._client.connection.server_info
         return (
-            f'{server_info.version_major}.{server_info.version_minor}.{server_info.version_patch}'
+            f"{server_info.version_major}.{server_info.version_minor}.{server_info.version_patch}"
         )
 
 

dbt/adapters/clickhouse/relation.py

@@ -7,6 +7,7 @@
 from dbt_common.exceptions import DbtRuntimeError
 from dbt_common.utils import deep_merge
 
+from dbt.adapters.clickhouse.logger import logger
 from dbt.adapters.clickhouse.query import quote_identifier
 
 NODE_TYPE_SOURCE = 'source'
@@ -127,6 +128,11 @@ def create_from(
                 relation_config.config.get('engine') if relation_config.config.get('engine') else ''
             )
             can_on_cluster = cls.get_on_cluster(cluster, materialized, engine)
+            if quoting.credentials.driver == "chdb":
+                logger.debug("Driver is chDB, forcing engine to be MergeTree")
+                engine = "MergeTree"
+                relation_config.config.engine = engine
+                can_on_cluster = False
 
         return cls.create(
             database='',

examples/taxis/README.md

@@ -32,7 +32,7 @@ CREATE TABLE taxis.trips (
 )
 ENGINE = MergeTree
 ORDER BY trip_id;
-  
+
 SET input_format_skip_unknown_fields = 1;
 
 INSERT INTO taxis.trips
@@ -62,26 +62,25 @@ FROM s3(
 
 ## Create a dbt profile entry
 
-Use the following profile to create the associated dbt profile in the  dbt_profiles.yml in ~/.dbt
+Use the following profile to create the associated dbt profile in the dbt_profiles.yml in ~/.dbt
+
 ```yml
 taxis:
   outputs:
-
     dev:
       type: clickhouse
-      threads: 4 
+      threads: 4
       host: localhost
-      port: 8123 
+      port: 8123
       user: dbt_test
       password: dbt_password
       use_lw_deletes: true
-      schema: taxis_dbt 
+      schema: taxis_dbt
 
   target: dev
-
 ```
 
 ## Run the model
 
-`dbt run` in this directory should execute the model.  Each run will create a somewhat larger dataset (by adding
+`dbt run` in this directory should execute the model. Each run will create a somewhat larger dataset (by adding
 additional random trip_ids).

examples/taxis/dump/taxi.sql

@@ -0,0 +1,23 @@
+CREATE DATABASE taxis;
+
+CREATE TABLE taxis.trips (
+    trip_id             UInt32,
+    pickup_datetime     DateTime,
+    dropoff_datetime    DateTime,
+    pickup_longitude    Nullable(Float64),
+    pickup_latitude     Nullable(Float64),
+    dropoff_longitude   Nullable(Float64),
+    dropoff_latitude    Nullable(Float64),
+    passenger_count     UInt8,
+    trip_distance       Float32,
+    fare_amount         Float32,
+    extra               Float32,
+    tip_amount          Float32,
+    tolls_amount        Float32,
+    total_amount        Float32,
+    payment_type        LowCardinality(String),
+    pickup_ntaname      LowCardinality(String),
+    dropoff_ntaname     LowCardinality(String)
+)
+ENGINE = MergeTree
+ORDER BY trip_id;