oracle

create database:
create database test …

create sequence
create sequence seq_test
minvalue 1
maxvalue 99999999
increment by 1
start with 1
nocache
order no cycle;

create tablespace
create tablespace tbs_test
datafile ‘D:\oracle\product\10.2.0\oracle\test\tbs_test.dbf’
size 50M
autoextend on next 50M
maxsize unlimited;

tablespace_info
SELECT
t.tablespace_name,
ROUND(SUM(bytes/(1024*1024)),0) ts_size
FROM
dba_tablespaces t,
dba_data_files d
WHERE
t.tablespace_name=d.tablespace_name
GROUP BY
t.tablespace_name;

==================未完待续＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
mysql: select nextval(‘seqname’) as seq;
oracle: select sqlname.nextval as seq from dual;
db2 : select nextval for seqname as seq from sysibm.sysdumy1;