allows data type diff and ensures valid migration separately

dlt/cli/command_wrappers.py

@@ -43,14 +43,14 @@ def init_command_wrapper(
     destination_type: str,
     repo_location: str,
     branch: str,
-    omit_core_sources: bool = False,
+    eject_source: bool = False,
 ) -> None:
     init_command(
         source_name,
         destination_type,
         repo_location,
         branch,
-        omit_core_sources,
+        eject_source,
     )
 
 

dlt/cli/init_command.py

@@ -157,7 +157,7 @@ def _list_core_sources() -> Dict[str, SourceConfiguration]:
     sources: Dict[str, SourceConfiguration] = {}
     for source_name in files_ops.get_sources_names(core_sources_storage, source_type="core"):
         sources[source_name] = files_ops.get_core_source_configuration(
-            core_sources_storage, source_name
+            core_sources_storage, source_name, eject_source=False
         )
     return sources
 
@@ -295,7 +295,7 @@ def init_command(
     destination_type: str,
     repo_location: str,
     branch: str = None,
-    omit_core_sources: bool = False,
+    eject_source: bool = False,
 ) -> None:
     # try to import the destination and get config spec
     destination_reference = Destination.from_reference(destination_type)
@@ -310,13 +310,9 @@ def init_command(
 
     # discover type of source
     source_type: files_ops.TSourceType = "template"
-    if (
-        source_name in files_ops.get_sources_names(core_sources_storage, source_type="core")
-    ) and not omit_core_sources:
+    if source_name in files_ops.get_sources_names(core_sources_storage, source_type="core"):
         source_type = "core"
     else:
-        if omit_core_sources:
-            fmt.echo("Omitting dlt core sources.")
         verified_sources_storage = _clone_and_get_verified_sources_storage(repo_location, branch)
         if source_name in files_ops.get_sources_names(
             verified_sources_storage, source_type="verified"
@@ -380,7 +376,7 @@ def init_command(
     else:
         if source_type == "core":
             source_configuration = files_ops.get_core_source_configuration(
-                core_sources_storage, source_name
+                core_sources_storage, source_name, eject_source
             )
             from importlib.metadata import Distribution
 
@@ -392,6 +388,9 @@ def init_command(
 
             if canonical_source_name in extras:
                 source_configuration.requirements.update_dlt_extras(canonical_source_name)
+
+            #  create remote modified index to copy files when ejecting
+            remote_modified = {file_name: None for file_name in source_configuration.files}
         else:
             if not is_valid_schema_name(source_name):
                 raise InvalidSchemaName(source_name)
@@ -536,11 +535,17 @@ def init_command(
                 "Creating a new pipeline with the dlt core source %s (%s)"
                 % (fmt.bold(source_name), source_configuration.doc)
             )
-            fmt.echo(
-                "NOTE: Beginning with dlt 1.0.0, the source %s will no longer be copied from the"
-                " verified sources repo but imported from dlt.sources. You can provide the"
-                " --omit-core-sources flag to revert to the old behavior." % (fmt.bold(source_name))
-            )
+            if eject_source:
+                fmt.echo(
+                    "NOTE: Source code of %s will be ejected. Remember to modify the pipeline "
+                    "example script to import the ejected source." % (fmt.bold(source_name))
+                )
+            else:
+                fmt.echo(
+                    "NOTE: Beginning with dlt 1.0.0, the source %s will no longer be copied from"
+                    " the verified sources repo but imported from dlt.sources. You can provide the"
+                    " --eject flag to revert to the old behavior." % (fmt.bold(source_name))
+                )
         elif source_configuration.source_type == "verified":
             fmt.echo(
                 "Creating and configuring a new pipeline with the verified source %s (%s)"

dlt/cli/pipeline_files.py

@@ -226,19 +226,39 @@ def get_template_configuration(
     )
 
 
+def _get_source_files(sources_storage: FileStorage, source_name: str) -> List[str]:
+    """Get all files that belong to source `source_name`"""
+    files: List[str] = []
+    for root, subdirs, _files in os.walk(sources_storage.make_full_path(source_name)):
+        # filter unwanted files
+        for subdir in list(subdirs):
+            if any(fnmatch.fnmatch(subdir, ignore) for ignore in IGNORE_FILES):
+                subdirs.remove(subdir)
+        rel_root = sources_storage.to_relative_path(root)
+        files.extend(
+            [
+                os.path.join(rel_root, file)
+                for file in _files
+                if all(not fnmatch.fnmatch(file, ignore) for ignore in IGNORE_FILES)
+            ]
+        )
+    return files
+
+
 def get_core_source_configuration(
-    sources_storage: FileStorage, source_name: str
+    sources_storage: FileStorage, source_name: str, eject_source: bool
 ) -> SourceConfiguration:
     src_pipeline_file = CORE_SOURCE_TEMPLATE_MODULE_NAME + "/" + source_name + PIPELINE_FILE_SUFFIX
     dest_pipeline_file = source_name + PIPELINE_FILE_SUFFIX
+    files: List[str] = _get_source_files(sources_storage, source_name) if eject_source else []
 
     return SourceConfiguration(
         "core",
         "dlt.sources." + source_name,
         sources_storage,
         src_pipeline_file,
         dest_pipeline_file,
-        [".gitignore"],
+        files,
         SourceRequirements([]),
         _get_docstring_for_module(sources_storage, source_name),
         False,
@@ -259,21 +279,7 @@ def get_verified_source_configuration(
             f"Pipeline example script {example_script} could not be found in the repository",
             source_name,
         )
-    # get all files recursively
-    files: List[str] = []
-    for root, subdirs, _files in os.walk(sources_storage.make_full_path(source_name)):
-        # filter unwanted files
-        for subdir in list(subdirs):
-            if any(fnmatch.fnmatch(subdir, ignore) for ignore in IGNORE_FILES):
-                subdirs.remove(subdir)
-        rel_root = sources_storage.to_relative_path(root)
-        files.extend(
-            [
-                os.path.join(rel_root, file)
-                for file in _files
-                if all(not fnmatch.fnmatch(file, ignore) for ignore in IGNORE_FILES)
-            ]
-        )
+    files = _get_source_files(sources_storage, source_name)
     # read requirements
     requirements_path = os.path.join(source_name, utils.REQUIREMENTS_TXT)
     if sources_storage.has_file(requirements_path):

dlt/cli/plugins.py

@@ -84,14 +84,10 @@ def configure_parser(self, parser: argparse.ArgumentParser) -> None:
         )
 
         parser.add_argument(
-            "--omit-core-sources",
+            "--eject",
             default=False,
             action="store_true",
-            help=(
-                "When present, will not create the new pipeline with a core source of the given"
-                " name but will take a source of this name from the default or provided"
-                " location."
-            ),
+            help="Ejects the source code of the core source like sql_database",
         )
 
     def execute(self, args: argparse.Namespace) -> None:
@@ -107,7 +103,7 @@ def execute(self, args: argparse.Namespace) -> None:
                     args.destination,
                     args.location,
                     args.branch,
-                    args.omit_core_sources,
+                    args.eject,
                 )
 
 

dlt/common/schema/utils.py

@@ -457,35 +457,15 @@ def diff_table(
     * when columns with the same name have different data types
     * when table links to different parent tables
     """
-    if tab_a["name"] != tab_b["name"]:
-        raise TablePropertiesConflictException(
-            schema_name, tab_a["name"], "name", tab_a["name"], tab_b["name"]
-        )
-    table_name = tab_a["name"]
-    # check if table properties can be merged
-    if tab_a.get("parent") != tab_b.get("parent"):
-        raise TablePropertiesConflictException(
-            schema_name, table_name, "parent", tab_a.get("parent"), tab_b.get("parent")
-        )
+    # allow for columns to differ
+    ensure_compatible_tables(schema_name, tab_a, tab_b, ensure_columns=False)
 
     # get new columns, changes in the column data type or other properties are not allowed
     tab_a_columns = tab_a["columns"]
     new_columns: List[TColumnSchema] = []
     for col_b_name, col_b in tab_b["columns"].items():
         if col_b_name in tab_a_columns:
             col_a = tab_a_columns[col_b_name]
-            # we do not support changing data types of columns
-            if is_complete_column(col_a) and is_complete_column(col_b):
-                if not compare_complete_columns(tab_a_columns[col_b_name], col_b):
-                    # attempt to update to incompatible columns
-                    raise CannotCoerceColumnException(
-                        schema_name,
-                        table_name,
-                        col_b_name,
-                        col_b["data_type"],
-                        tab_a_columns[col_b_name]["data_type"],
-                        None,
-                    )
             # all other properties can change
             merged_column = merge_column(copy(col_a), col_b)
             if merged_column != col_a:
@@ -494,6 +474,8 @@ def diff_table(
             new_columns.append(col_b)
 
     # return partial table containing only name and properties that differ (column, filters etc.)
+    table_name = tab_a["name"]
+
     partial_table: TPartialTableSchema = {
         "name": table_name,
         "columns": {} if new_columns is None else {c["name"]: c for c in new_columns},
@@ -519,6 +501,50 @@ def diff_table(
     return partial_table
 
 
+def ensure_compatible_tables(
+    schema_name: str, tab_a: TTableSchema, tab_b: TPartialTableSchema, ensure_columns: bool = True
+) -> None:
+    """Ensures that `tab_a` and `tab_b` can be merged without conflicts. Conflicts are detected when
+
+    - tables have different names
+    - nested tables have different parents
+    - tables have any column with incompatible types
+
+    Note: all the identifiers must be already normalized
+
+    """
+    if tab_a["name"] != tab_b["name"]:
+        raise TablePropertiesConflictException(
+            schema_name, tab_a["name"], "name", tab_a["name"], tab_b["name"]
+        )
+    table_name = tab_a["name"]
+    # check if table properties can be merged
+    if tab_a.get("parent") != tab_b.get("parent"):
+        raise TablePropertiesConflictException(
+            schema_name, table_name, "parent", tab_a.get("parent"), tab_b.get("parent")
+        )
+
+    if not ensure_columns:
+        return
+
+    tab_a_columns = tab_a["columns"]
+    for col_b_name, col_b in tab_b["columns"].items():
+        if col_b_name in tab_a_columns:
+            col_a = tab_a_columns[col_b_name]
+            # we do not support changing data types of columns
+            if is_complete_column(col_a) and is_complete_column(col_b):
+                if not compare_complete_columns(tab_a_columns[col_b_name], col_b):
+                    # attempt to update to incompatible columns
+                    raise CannotCoerceColumnException(
+                        schema_name,
+                        table_name,
+                        col_b_name,
+                        col_b["data_type"],
+                        tab_a_columns[col_b_name]["data_type"],
+                        None,
+                    )
+
+
 # def compare_tables(tab_a: TTableSchema, tab_b: TTableSchema) -> bool:
 #     try:
 #         table_name = tab_a["name"]

dlt/normalize/normalize.py

@@ -20,7 +20,7 @@
     LoadStorage,
     ParsedLoadJobFileName,
 )
-from dlt.common.schema import TSchemaUpdate, Schema
+from dlt.common.schema import Schema
 from dlt.common.schema.exceptions import CannotCoerceColumnException
 from dlt.common.pipeline import (
     NormalizeInfo,
@@ -34,7 +34,7 @@
 from dlt.normalize.configuration import NormalizeConfiguration
 from dlt.normalize.exceptions import NormalizeJobFailed
 from dlt.normalize.worker import w_normalize_files, group_worker_files, TWorkerRV
-from dlt.normalize.validate import verify_normalized_table
+from dlt.normalize.validate import validate_and_update_schema, verify_normalized_table
 
 
 # normalize worker wrapping function signature
@@ -80,16 +80,6 @@ def create_storages(self) -> None:
             config=self.config._load_storage_config,
         )
 
-    def update_schema(self, schema: Schema, schema_updates: List[TSchemaUpdate]) -> None:
-        for schema_update in schema_updates:
-            for table_name, table_updates in schema_update.items():
-                logger.info(
-                    f"Updating schema for table {table_name} with {len(table_updates)} deltas"
-                )
-                for partial_table in table_updates:
-                    # merge columns where we expect identifiers to be normalized
-                    schema.update_table(partial_table, normalize_identifiers=False)
-
     def map_parallel(self, schema: Schema, load_id: str, files: Sequence[str]) -> TWorkerRV:
         workers: int = getattr(self.pool, "_max_workers", 1)
         chunk_files = group_worker_files(files, workers)
@@ -123,7 +113,7 @@ def map_parallel(self, schema: Schema, load_id: str, files: Sequence[str]) -> TW
                     result: TWorkerRV = pending.result()
                     try:
                         # gather schema from all manifests, validate consistency and combine
-                        self.update_schema(schema, result[0])
+                        validate_and_update_schema(schema, result[0])
                         summary.schema_updates.extend(result.schema_updates)
                         summary.file_metrics.extend(result.file_metrics)
                         # update metrics
@@ -162,7 +152,7 @@ def map_single(self, schema: Schema, load_id: str, files: Sequence[str]) -> TWor
             load_id,
             files,
         )
-        self.update_schema(schema, result.schema_updates)
+        validate_and_update_schema(schema, result.schema_updates)
         self.collector.update("Files", len(result.file_metrics))
         self.collector.update(
             "Items", sum(result.file_metrics, EMPTY_DATA_WRITER_METRICS).items_count
@@ -237,23 +227,11 @@ def spool_schema_files(self, load_id: str, schema: Schema, files: Sequence[str])
         self.load_storage.import_extracted_package(
             load_id, self.normalize_storage.extracted_packages
         )
-        logger.info(f"Created new load package {load_id} on loading volume")
-        try:
-            # process parallel
-            self.spool_files(
-                load_id, schema.clone(update_normalizers=True), self.map_parallel, files
-            )
-        except CannotCoerceColumnException as exc:
-            # schema conflicts resulting from parallel executing
-            logger.warning(
-                f"Parallel schema update conflict, switching to single thread ({str(exc)}"
-            )
-            # start from scratch
-            self.load_storage.new_packages.delete_package(load_id)
-            self.load_storage.import_extracted_package(
-                load_id, self.normalize_storage.extracted_packages
-            )
-            self.spool_files(load_id, schema.clone(update_normalizers=True), self.map_single, files)
+        logger.info(f"Created new load package {load_id} on loading volume with ")
+        # get number of workers with default == 1 if not set (ie. NullExecutor)
+        workers: int = getattr(self.pool, "_max_workers", 1)
+        map_f: TMapFuncType = self.map_parallel if workers > 1 else self.map_single
+        self.spool_files(load_id, schema.clone(update_normalizers=True), map_f, files)
 
         return load_id
 

dlt/normalize/validate.py

@@ -1,7 +1,10 @@
+from typing import List
+
 from dlt.common.destination.capabilities import DestinationCapabilitiesContext
 from dlt.common.schema import Schema
-from dlt.common.schema.typing import TTableSchema
+from dlt.common.schema.typing import TTableSchema, TSchemaUpdate
 from dlt.common.schema.utils import (
+    ensure_compatible_tables,
     find_incomplete_columns,
     get_first_column_name_with_prop,
     is_nested_table,
@@ -10,6 +13,21 @@
 from dlt.common import logger
 
 
+def validate_and_update_schema(schema: Schema, schema_updates: List[TSchemaUpdate]) -> None:
+    """Updates `schema` tables with partial tables in `schema_updates`"""
+    for schema_update in schema_updates:
+        for table_name, table_updates in schema_update.items():
+            logger.info(f"Updating schema for table {table_name} with {len(table_updates)} deltas")
+            for partial_table in table_updates:
+                # ensure updates will pass
+                if existing_table := schema.tables.get(partial_table["name"]):
+                    ensure_compatible_tables(schema.name, existing_table, partial_table)
+
+            for partial_table in table_updates:
+                # merge columns where we expect identifiers to be normalized
+                schema.update_table(partial_table, normalize_identifiers=False)
+
+
 def verify_normalized_table(
     schema: Schema, table: TTableSchema, capabilities: DestinationCapabilitiesContext
 ) -> None: