feat(ingest/datahub): use stream_results with mysql (#12278)

Author: hsheth2

metadata-ingestion/setup.py

@@ -461,7 +461,7 @@
     "mssql-odbc": sql_common | mssql_common | {"pyodbc"},
     "mysql": mysql,
     # mariadb should have same dependency as mysql
-    "mariadb": sql_common | {"pymysql>=1.0.2"},
+    "mariadb": sql_common | mysql,
     "okta": {"okta~=1.7.0", "nest-asyncio"},
     "oracle": sql_common | {"oracledb"},
     "postgres": sql_common | postgres_common,

metadata-ingestion/src/datahub/ingestion/source/datahub/config.py

@@ -1,6 +1,7 @@
 import os
 from typing import Optional, Set
 
+import pydantic
 from pydantic import Field, root_validator
 
 from datahub.configuration.common import AllowDenyPattern
@@ -119,3 +120,12 @@ def check_ingesting_data(cls, values):
                 " Please specify at least one of `database_connection` or `kafka_connection`, ideally both."
             )
         return values
+
+    @pydantic.validator("database_connection")
+    def validate_mysql_scheme(
+        cls, v: SQLAlchemyConnectionConfig
+    ) -> SQLAlchemyConnectionConfig:
+        if "mysql" in v.scheme:
+            if v.scheme != "mysql+pymysql":
+                raise ValueError("For MySQL, the scheme must be mysql+pymysql.")
+        return v

metadata-ingestion/src/datahub/ingestion/source/datahub/datahub_database_reader.py

@@ -151,31 +151,17 @@ def execute_server_cursor(
         self, query: str, params: Dict[str, Any]
     ) -> Iterable[Dict[str, Any]]:
         with self.engine.connect() as conn:
-            if self.engine.dialect.name == "postgresql":
+            if self.engine.dialect.name in ["postgresql", "mysql", "mariadb"]:
                 with conn.begin():  # Transaction required for PostgreSQL server-side cursor
+                    # Note that stream_results=True is mainly supported by PostgreSQL and MySQL-based dialects.
+                    # https://docs.sqlalchemy.org/en/14/core/connections.html#sqlalchemy.engine.Connection.execution_options.params.stream_results
                     conn = conn.execution_options(
                         stream_results=True,
                         yield_per=self.config.database_query_batch_size,
                     )
                     result = conn.execute(query, params)
                     for row in result:
                         yield dict(row)
-            elif self.engine.dialect.name == "mysql":  # MySQL
-                import MySQLdb
-
-                with contextlib.closing(
-                    conn.connection.cursor(MySQLdb.cursors.SSCursor)
-                ) as cursor:
-                    logger.debug(f"Using Cursor type: {cursor.__class__.__name__}")
-                    cursor.execute(query, params)
-
-                    columns = [desc[0] for desc in cursor.description]
-                    while True:
-                        rows = cursor.fetchmany(self.config.database_query_batch_size)
-                        if not rows:
-                            break  # Use break instead of return in generator
-                        for row in rows:
-                            yield dict(zip(columns, row))
             else:
                 raise ValueError(f"Unsupported dialect: {self.engine.dialect.name}")
 

metadata-ingestion/src/datahub/ingestion/source/datahub/datahub_source.py

@@ -130,7 +130,7 @@ def _get_database_workunits(
             self._commit_progress(i)
 
     def _get_kafka_workunits(
-        self, from_offsets: Dict[int, int], soft_deleted_urns: List[str] = []
+        self, from_offsets: Dict[int, int], soft_deleted_urns: List[str]
     ) -> Iterable[MetadataWorkUnit]:
         if self.config.kafka_connection is None:
             return