Timestamps are cumbersome to modify:

drop table t;

Table dropped.

create table t as select systimestamp ts from dual;

Table created.

alter table t modify ts timestamp (0);
alter table t modify ts timestamp (0)
*
ERROR at line 1:
ORA-01439: column to be modified must be empty to change datatype


alter table t modify ts timestamp (9);
alter table t modify ts timestamp (9)
*
ERROR at line 1:
ORA-01439: column to be modified must be empty to change datatype

>> ... changing the size would require rewriting the ENTIRE table (unless they are all null)

I still wish we had the option to override the "no non-null values" check though, and just take any pain associated with the required changes. I suppose that the major issues would be migrated rows, a locked table, a potentially high i/o load, data segment compression issues, and having to deal with indexes.

To not be able to for the sake of one non-null value out of fifty gazillion null values is a frustration. I'm not saying there isn't a way round it, or that it's particularly onerous, but there are cases when it would be a useful option.

Hi Tom,
machine1 time;9:10 am(client)
machine2 time: 11:00 am(server)

When we connect from machine1(client) to machine2(server) the server time is displayed from systimestamp,current_timestamp and localtimestamp.
########
11:00
#########

How could I see the time of client machine that is
#####
9:10
#####


I think if we know client machine's time zone then we can find from below query.
###########
SELECT SYSTIMESTAMP AT TIME ZONE '+00:00' from dual;
###########
But can we get it dierctly
Is there any direct identifer something like client_timestamp ,so we can get client machine timestamp.

thanks