--create table
create table table_name (
column1 varchar2(20) not null,
column2 number(8) not null,
column3 date,
column4 char
)
--define space
tablespace base_data
pctfree 10
initrans 1
maxtrans 255
storage
(
initial 64K,
next 1M,
minextents 1,
maxextents unlimited
);
--add comment
comment on column to table_name.column1
is 'this is the column comment';
...