Copying a table with an all-NULL UUID column fails

[hombit]

Reproducible example, tested with version 0.4.0 (from github tag), postgres 15

# CREATE TEMP TABLE test (
    x UUID
);
# INSERT INTO test (x) VALUES
    (NULL),
    (NULL);
# COPY test TO '/tmp/uuid.parquet' (format 'parquet');
ERROR:  Expected record batch: InvalidArgumentError("column types must match schema types, expected FixedSizeBinary(16) but found FixedSizeBinary(0) at column index 0")

[bradymholt]

I just hit this on version 0.4.0 on a table that has several uuid fields including a uuid PK. I am surprised I hit this error on a table that has uuid PK since it looks like this issue happens when all uuid fields are NULL.

Error I received:

Expected record batch: InvalidArgumentError("column types must match schema types, expected FixedSizeBinary(16) but found FixedSizeBinary(0) at column index 3")

Is there a way to work around this error until #144 is incorporated into a release?

[aykut-bozkurt]

I just hit this on version 0.4.0 on a table that has several uuid fields including a uuid PK. I am surprised I hit this error on a table that has uuid PK since it looks like this issue happens when all uuid fields are NULL.

Error I received:

Expected record batch: InvalidArgumentError("column types must match schema types, expected FixedSizeBinary(16) but found FixedSizeBinary(0) at column index 3")

Is there a way to work around this error until #144 is incorporated into a release?

That means one of the uuid fields contains all null values. I plan to release 0.5.0 less than a month if we find review bandwidth for the open PRs.

[bradymholt]

one of the uuid fields contains all null values

So, you would expect to see this if all rows in a table have a NULL value for one of the uuid fields? I have a table with 3 uuid fields, one of which is the primary key. I've found records in the table that have a non-NULL value for each of the 2 uuid fields so I am sure the table does not have NULL values for all rows in these fields. Is it possible the issue manifests in different ways? Also, if you know a way to work around this I would appreciate it.