What will the datetime data type

[BohuTANG]

@sundy-li @Veeupup

What's the databend final datetime data type is？
In some database systems(snow, bigquery, duckdb, cockroachdb), they are introduce only one type: timestamp(datetime may be a aliases name in some of them), and the range:

0001-01-01 00:00:00 to 9999-12-31 23:59:59.999999 UTC

Supports precision levels from 0 (seconds) to 6 (microseconds) .

I suggest the default is TIMESTAMP(6), what do you think?

Originally posted by @BohuTANG in #4982 (comment)

[sundy-li]

I think TIMESTAMP is aliased to DATETIME.

Cockroachdb has custom precision, Timestamp(n):
eg:

CREATE TABLE timestamps (a INT PRIMARY KEY, b TIMESTAMP(3));

[BohuTANG]

OK.
Then the problem is what the default date time value is?

[sundy-li]

I checked bigquery and Cockroachdb , we can make the default precision to be 6.

DateTime equals to DateTime(6), Timestamp(6), Timestamp , @Veeupup

The range of precision is [0, 9] is ok.