I understand that DDL statements in Oracle have an implicit commit before and after the statement, which obviously affects the current transaction.
However, does a DDL statement in any way affect other transactions running against that table (assuming the change is compatible with the DML running against the table)?
For example, if I decide to
varchar2(10) columnn to
varchar2(20), or add a new column altogether, or drop an obsolete, no longer used column -- are other transactions going to be happy about it, or is there going to be any sort of contention or interruption of running transactions?