Hive Connector. Translate Empty Value in NULL in Text Files

[larandvit]

Hello,

I can't find a setting to instruct PrestoSQL in CREATE TABLE statement that I want empty values in text files to be interpreted as NULLS.

It's used Hive connector with access to Minio S3 storage.

Create table statement

CREATE TABLE minio.lab.sample_table(
    column1 varchar,
    column2 intger)
WITH (
      external_location = 's3a://bucket-name/folder-name',
      format = 'TEXTFILE',
      skip_header_line_count=1
);

In Hive table, it can accomplished by 'serialization.null.format'='' property in TBLPROPERTIES section.

Thanks.
Vitaly.

[findepi]

If you set serialization.null.format table property via Hive, are you getting the results you expect from Presto?

[larandvit]

Thank you for a quick response.

Data located in Minio storage. It's compatible to S3. PrestoDB connected to Minio with Hive connector. I provided serialization.null.format setting as a sample what we need to get because it's used Hive connector and it should behave similar to Hive.

What a setting do we need to apply to interpret empty values in a text file as NULL values in PrestoDB?

Sample of a text file with empty value in "Col2".

Col1,Col2,Col3
19,,sample test

[findepi]

While we want to make it very easy to use the most commonly used features, i have to say that serialization.null.format is currently not one of the common.
I think this should be addressed with #954.

[larandvit]

Thank you, @findepi , for updates.

[JeevansSP]

@findepi hello, has this been added yet?