Hi Experts,
I encounter the following issues.
1. Try to create a column table with a DATE type column, and insert some values.
CREATE COLUMN TABLE test1(D DATE); INSERT INTO test1(D) VALUES (CURRENT_DATE); SELECT D, length(D) FROM test1;
The result would be like:
D length(D) ---- ------ Dec 8, 2014 10
2. Try to change the type of column D from DATE to NVARCHAR(8), and it did work.
ALTER TABLE TEST1 ALTER(D NVARCHAR(8)); SELECT D, length(D) FROM test1
The result would be like:
D length(D) ---- ------ 2014-12-08 10
3. Try to insert a string with more than 8 characters into table, but failed.
insert into TEST1 values(to_nvarchar(current_date));
Could not execute 'insert into TEST1 values(to_nvarchar(current_date))' in 258 ms 23 µs .
SAP DBTech JDBC: [274]: inserted value too large for column: Failed in "D" column with the value '2014-12-08'
Questions:
Why is it possible that HANA still keeps the original record of DATE type with length greater than 8(in this case 10) after the column type has changed to NVARCHAR(8)? I assume it would either not allow to change the column type from DATE to NVARCHAR(8) because it contains a record with length greater than 8, or it would just drop the record or change it to other format, something like that?
Appreciated for any input. 
Thanks and Regards,
Aron