Data Type: `NUMERIC`

[amotl]

About

CrateDB gained a new data type NUMERIC. Most probably, we want to support it here in one way or another.

References

• Data Type: NUMERIC sqlalchemy-cratedb#163

[amotl]

It is probably still the right choice to serialize Decimal values as strings, because there is no other way to marshal them through JSON?

crate-python/src/crate/client/http.py

Lines 95 to 96 in 8a3bf38

	if isinstance(o, (Decimal, UUID)):
	return str(o)

In this case, I guess it will be safe to close this issue for the DB API driver, but check crate/sqlalchemy-cratedb#163 instead, if there is something to do for SQLAlchemy, which is more likely?

/cc @matriv, @seut

[matriv]

If we have the same behavior that we encountered here: crate/crate#16843
I agree to go with strings.

[amotl]

Thank you. Then, there will be nothing to update or improve, other than the documentation perhaps, also on the Python driver at a relevant spot?

-- crate/crate#16843

As you advise that HTTP/JSON transport may loose precision, may I ask if it would be expectably different when using the PostgreSQL interface?

[seut]

As you advise that HTTP/JSON transport may loose precision, may I ask if it would be expectably different when using the PostgreSQL interface?

Yes, the issue is completely related to HTTP/JSON only.

[matriv]

and to be more precise, http streams the full number (reaches the client), but the application/json MIME type directive is the one that truncates digits.

[seut]

As CrateDB supports NUMERIC/DECIMAL types for quite some time (only the support to store numeric values was added recently), I wonder what this issue is about, what is missing?

Probably we want to change the related test case to use a NUMERIC column data type in the table definition.