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Remove workaround for _-prefixed column names #57

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2 changes: 2 additions & 0 deletions CHANGES.md
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Expand Up @@ -3,6 +3,8 @@
## In progress
- Add support for container types `ARRAY`, `OBJECT`, and `FLOAT_VECTOR`.
- Improve write operations to be closer to `target-postgres`.
- Removed workaround for `_`-prefixed column names.
The package now requires CrateDB 6.2 or higher.

## 2023-12-08 v0.0.1
- Make it work. It can run the canonical Meltano GitHub -> DB example.
1 change: 1 addition & 0 deletions README.md
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Expand Up @@ -18,6 +18,7 @@ and loaders, and based on the [Meltano PostgreSQL target].
In order to learn more about Singer, Meltano, and friends, navigate to the
[Singer Intro](./docs/singer-intro.md).

Operating the package successfully needs CrateDB 6.2 or higher.
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@amotl amotl Nov 10, 2025 •
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Hi @surister. Thanks. Let me loop your comment into a thread.

Should we perhaps maintain this and check for CrateDB version? I assume that this will break people trying to use it with CrateDB < 6.2.

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@amotl amotl Nov 10, 2025

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Yes, it will not work with lower versions of CrateDB. As I see the CrateDB 6.2 release might be far away (expecting 6.1 first?), this patch is probably not ready for releasing, and should be made a draft again?

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@amotl amotl Nov 10, 2025 •
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I am not sure about pre-flight checks. I haven't seen many (if any) such measures in other vendor's adapters. In a perfect world, this adapter will vanish completely anyway if we could submit all specialities into the upstream target-postgres.

However, I see your point, and, as long as we maintain a separate adapter, and, most importantly, as long as it will not have a negative performance impact in high-traffic or high-volume environments, I will not object adding conveniency features like pre-flight version checks.

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@amotl amotl Nov 10, 2025 •
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This patch includes a check for the CrateDB version, as suggested.

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@amotl amotl Nov 11, 2025 •
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NB: The package is in alpha/workbench mode, currently bearing just 46 downloads per month. In this spirit, we can easily produce (merge & release) this improvement, to make it a fully functional and significantly enhanced package for all users of CrateDB nightly and future CrateDB 6.2 users, even if this will only be released in Jan/Feb 2026.

All people who are currently using the package can easily stick with the currently released version. There is not much need to introduce or address backward compatibility issues.


## Install

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90 changes: 0 additions & 90 deletions target_cratedb/sinks.py
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@@ -1,8 +1,6 @@
"""CrateDB target sink class, which handles writing streams."""

import datetime
import os
import time
from typing import List, Optional, Union

import sqlalchemy as sa
Expand All @@ -20,9 +18,6 @@ class CrateDBSink(PostgresSink):

connector_class = CrateDBConnector

soft_delete_column_name = "__sdc_deleted_at"
version_column_name = "__sdc_table_version"

def __init__(self, *args, **kwargs):
"""Initialize SQL Sink. See super class for more details."""
super().__init__(*args, **kwargs)
Expand All @@ -32,91 +27,6 @@ def __init__(self, *args, **kwargs):
# operations on the target table.
self.strategy_direct = MELTANO_CRATEDB_STRATEGY_DIRECT

# Record processing

def _add_sdc_metadata_to_record(
self,
record: dict,
message: dict,
context: dict,
) -> None:
"""Populate metadata _sdc columns from incoming record message.

Record metadata specs documented at:
https://sdk.meltano.com/en/latest/implementation/record_metadata.html

Args:
record: Individual record in the stream.
message: The record message.
context: Stream partition or context dictionary.
"""
record["__sdc_extracted_at"] = message.get("time_extracted")
record["__sdc_received_at"] = datetime.datetime.now(
tz=datetime.timezone.utc,
).isoformat()
record["__sdc_batched_at"] = (
context.get("batch_start_time", None) or datetime.datetime.now(tz=datetime.timezone.utc)
).isoformat()
record["__sdc_deleted_at"] = record.get("__sdc_deleted_at")
record["__sdc_sequence"] = int(round(time.time() * 1000))
record["__sdc_table_version"] = message.get("version")
record["__sdc_sync_started_at"] = self.sync_started_at

def _add_sdc_metadata_to_schema(self) -> None:
"""Add _sdc metadata columns.

Record metadata specs documented at:
https://sdk.meltano.com/en/latest/implementation/record_metadata.html
"""
properties_dict = self.schema["properties"]
for col in (
"__sdc_extracted_at",
"__sdc_received_at",
"__sdc_batched_at",
"__sdc_deleted_at",
):
properties_dict[col] = {
"type": ["null", "string"],
"format": "date-time",
}
for col in ("__sdc_sequence", "__sdc_table_version", "__sdc_sync_started_at"):
properties_dict[col] = {"type": ["null", "integer"]}

def _remove_sdc_metadata_from_schema(self) -> None:
"""Remove _sdc metadata columns.

Record metadata specs documented at:
https://sdk.meltano.com/en/latest/implementation/record_metadata.html
"""
properties_dict = self.schema["properties"]
for col in (
"__sdc_extracted_at",
"__sdc_received_at",
"__sdc_batched_at",
"__sdc_deleted_at",
"__sdc_sequence",
"__sdc_table_version",
"__sdc_sync_started_at",
):
properties_dict.pop(col, None)

def _remove_sdc_metadata_from_record(self, record: dict) -> None:
"""Remove metadata _sdc columns from incoming record message.

Record metadata specs documented at:
https://sdk.meltano.com/en/latest/implementation/record_metadata.html

Args:
record: Individual record in the stream.
"""
record.pop("__sdc_extracted_at", None)
record.pop("__sdc_received_at", None)
record.pop("__sdc_batched_at", None)
record.pop("__sdc_deleted_at", None)
record.pop("__sdc_sequence", None)
record.pop("__sdc_table_version", None)
record.pop("__sdc_sync_started_at", None)

def process_batch(self, context: dict) -> None:
"""Process a batch with the given batch context.

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2 changes: 1 addition & 1 deletion target_cratedb/tests/test_standard_target.py
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Expand Up @@ -30,7 +30,7 @@
from importlib_resources import files as resource_files # type: ignore[no-redef]


METADATA_COLUMN_PREFIX = "__sdc"
METADATA_COLUMN_PREFIX = "_sdc"


@pytest.fixture(scope="session")
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