feat(ingest/teradata): Add option to not use file backed dict for vie…

…w definitions (datahub-project#9024)

metadata-ingestion/src/datahub/ingestion/source/sql/teradata.py

@@ -1,7 +1,7 @@
 import logging
 from dataclasses import dataclass
 from datetime import datetime
-from typing import Iterable, Optional, Set, Union
+from typing import Iterable, MutableMapping, Optional, Union
 
 # This import verifies that the dependencies are available.
 import teradatasqlalchemy  # noqa: F401
@@ -12,7 +12,6 @@
 
 from datahub.configuration.common import AllowDenyPattern
 from datahub.configuration.time_window_config import BaseTimeWindowConfig
-from datahub.emitter.mcp import MetadataChangeProposalWrapper
 from datahub.emitter.sql_parsing_builder import SqlParsingBuilder
 from datahub.ingestion.api.common import PipelineContext
 from datahub.ingestion.api.decorators import (
@@ -34,11 +33,7 @@
 from datahub.ingestion.source.usage.usage_common import BaseUsageConfig
 from datahub.ingestion.source_report.ingestion_stage import IngestionStageReport
 from datahub.ingestion.source_report.time_window import BaseTimeWindowReport
-from datahub.metadata._schema_classes import (
-    MetadataChangeEventClass,
-    SchemaMetadataClass,
-    ViewPropertiesClass,
-)
+from datahub.metadata._schema_classes import SchemaMetadataClass, ViewPropertiesClass
 from datahub.metadata.com.linkedin.pegasus2avro.schema import (
     BytesTypeClass,
     TimeTypeClass,
@@ -112,6 +107,11 @@ class TeradataConfig(BaseTeradataConfig, BaseTimeWindowConfig):
         description="Generate usage statistic.",
     )
 
+    use_file_backed_cache: bool = Field(
+        default=True,
+        description="Whether to use a file backed cache for the view definitions.",
+    )
+
 
 @platform_name("Teradata")
 @config_class(TeradataConfig)
@@ -142,7 +142,8 @@ class TeradataSource(TwoTierSQLAlchemySource):
      and "timestamp" >= TIMESTAMP '{start_time}'
      and "timestamp" < TIMESTAMP '{end_time}'
      """
-    urns: Optional[Set[str]]
+
+    _view_definition_cache: MutableMapping[str, str]
 
     def __init__(self, config: TeradataConfig, ctx: PipelineContext):
         super().__init__(config, ctx, "teradata")
@@ -166,7 +167,10 @@ def __init__(self, config: TeradataConfig, ctx: PipelineContext):
             env=self.config.env,
         )
 
-        self._view_definition_cache: FileBackedDict[str] = FileBackedDict()
+        if self.config.use_file_backed_cache:
+            self._view_definition_cache = FileBackedDict[str]()
+        else:
+            self._view_definition_cache = {}
 
     @classmethod
     def create(cls, config_dict, ctx):
@@ -249,24 +253,13 @@ def get_metadata_engine(self) -> Engine:
     def get_workunits_internal(self) -> Iterable[Union[MetadataWorkUnit, SqlWorkUnit]]:
         # Add all schemas to the schema resolver
         for wu in super().get_workunits_internal():
-            if isinstance(wu.metadata, MetadataChangeEventClass):
-                if wu.metadata.proposedSnapshot:
-                    for aspect in wu.metadata.proposedSnapshot.aspects:
-                        if isinstance(aspect, SchemaMetadataClass):
-                            self.schema_resolver.add_schema_metadata(
-                                wu.metadata.proposedSnapshot.urn,
-                                aspect,
-                            )
-                            break
-            if isinstance(wu.metadata, MetadataChangeProposalWrapper):
-                if (
-                    wu.metadata.entityUrn
-                    and isinstance(wu.metadata.aspect, ViewPropertiesClass)
-                    and wu.metadata.aspect.viewLogic
-                ):
-                    self._view_definition_cache[
-                        wu.metadata.entityUrn
-                    ] = wu.metadata.aspect.viewLogic
+            urn = wu.get_urn()
+            schema_metadata = wu.get_aspect_of_type(SchemaMetadataClass)
+            if schema_metadata:
+                self.schema_resolver.add_schema_metadata(urn, schema_metadata)
+            view_properties = wu.get_aspect_of_type(ViewPropertiesClass)
+            if view_properties and self.config.include_view_lineage:
+                self._view_definition_cache[urn] = view_properties.viewLogic
             yield wu
 
         if self.config.include_view_lineage: