bug: Source postgres json & jsonb columns loading to snowflake as varchar `true` when using meltanolabs tap-postgres and target-snowflake

[kyle-foerster]

Target Version

3.4.2

Python Version

3.9

PostgreSQL Version

16.4

Operating System

meltano/meltano:v3.4.2-python3.9 docker image

Description

Steps to fully reproduce can be found in this public repo. General configurations in this repo match our production env where we first noticed this behavior.

In swapping from using the transferwise variants of the tap-postgres and target-snowflake plugins to their respective meltanolabs variants, we noticed it will load any columns from the source of the json or jsonb data type to be varchar true in the target.

Source table was created with:

create table mix_data (
	id integer primary key,
	empty_data jsonb,
	data json
);

example source data in postgres:

example target data in Snowflake:

Quick matrix of what was tested. Only using the meltanolabs variant of both the tap-postgres and target-snowflake resulted in the malformed data.

tap-postgres variant	target-snowflake variant	Replicate correctly?
transferwise	transferwise	✅
transferwise	meltanolabs	✅
meltanolabs	transferwise	✅
meltanolabs	meltanolabs	❌

When looking at the schema of the actual messages that come across using the dummy data in the repo linked above, they look largely the same and what I'd expect. Not sure if including the boolean data type in the meltanolabs variant is somehow causing it to get read through incorrectly?

The schema from the meltanolabs tap-postgres:

"properties": {
            "id": {
                "type": ["integer"]
            },
            "empty_data": {
                "type": ["string","number","integer","array","object","boolean","null"]
            },
            "data": {
                "type": ["string","number","integer","array","object","boolean","null"]
            }
        },
        "type": "object",
        "required": ["id"]

Schema from the transferwise tap-postgres:

{
        "type": "object",
        "properties": {
            "id": {
                "type": ["integer"],
                "minimum": -2147483648,
                "maximum": 2147483647
            },
            "empty_data": {
                "type": ["null","object","array"]
            },
            "data": {
                "type": ["null","object","array"]
            }
        },
        "definitions": {
            "sdc_recursive_integer_array": {
                "type": ["null","object","array"],
                "items": {"$ref": "#/definitions/sdc_recursive_integer_array"}
            },
            "sdc_recursive_number_array": {
                "type": ["null","object","array"],
                "items": {"$ref": "#/definitions/sdc_recursive_number_array"}
            },
            "sdc_recursive_string_array": {
                "type": ["null","object","array"],
                "items": {"$ref": "#/definitions/sdc_recursive_string_array"}
            },
            "sdc_recursive_boolean_array": {
                "type": ["null","object","array"],
                "items": {"$ref": "#/definitions/sdc_recursive_boolean_array"}
            },
            "sdc_recursive_timestamp_array": {
                "type": ["null","object","array"],
                "format": "date-time",
                "items": {"$ref": "#/definitions/sdc_recursive_timestamp_array"}
            },
            "sdc_recursive_object_array": {
                "type": ["null","object","array"],
                "items": {"$ref": "#/definitions/sdc_recursive_object_array"}
            }
        }
    }

Link to Slack/Linen

https://meltano.slack.com/archives/C069CQNHDNF/p1728658002710249

[edgarrmondragon]

Hi @kyle-foerster, I've transferred this issue since you mention you're using target-snowflake.

Which version of tap-postgres are you using? i.e. what's the pip_url for that plugin?

[kyle-foerster]

Ah sorry about that, thanks for transferring.

What we're using matches what's in the example bug repo.

target-snowflake is using meltanolabs-target-snowflake
tap-postgres is using git+https://github.com/MeltanoLabs/tap-postgres.git

[edgarrmondragon]

Hey @kyle-foerster, thanks for the details!

This does sound like a relatively serious bug. I think I've narrowed it down to meltano/sdk#2726 upstream.

I'll try to come up with a failing test and a patch next week. If a fix upstream is hard to implement without introducing breaking changes, I'll then try a fix in this target.

[edgarrmondragon]

I just published 0.13.0b1 to PyPI, which should address this.