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DB，SQL，RDBMS

这个我来说句公道话。
前面大家讨论时都把DB，SQL，RDBMS混用，
你我也一样， 反正大家都明白就行， 不是写正式论文。 何况他
来浙版讨论，算是客人， 现在回过来这样说他就不厚道了。他虽然
不是DB专业， 但也算是CS出身，这些基本概念应该不至于不懂。

这里顺便向不是这行的老乡科普一下。 DB就是常说的Database，
中文叫数据库. 传统的数据库模型是E. F. Codd发明的Relational模型。
实现RDB(Relational DB)的软件管理系统，就是RDBMS， 比如ORACLE，
MYSQL， SQL SEVER， IBM DB2等。

RDB的查询语言基于Relational Algebra, 或Relationa Calculus，
相当于数学里的一阶逻辑。 SQL就是标准化的RDB的查询语言。
纯粹的SQL因为基于一阶逻辑， 所以不是图灵完备(Turing-complete)的。
但常用扩充的SQL是图灵完备的。

【 在 raki (Sela'ma ashal'anore!) 的大作中提到: 】
: 再说一遍，你很多概念不清。你前面那些帖子把DB，sql，RDBMS都等同起来。DB不光是
: RDBMS, document-oriented, federated，graph db都算，你要质疑可以发信问SIGMOD
: 。:D
: SQL不过是个language standard，没人会说它是个DB, nosql里面照样可以实现SQL。
: Hadoop当然不是一个DB，HBase才是。不过，你似乎认为作bigdata的公司非得是直接作
: Hadoop的, not true。
: DB architect不是DBA，我已经说了，需要heavy coding。
: 看似你也没有Internet startup经验，Internet startup有其特殊性，自开始处理的就
: 可以是PB级的。
: startup做过，才是真正多面手，哪里都能上。那谁要说跳出db框架，容易的很，去
: ...................
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