哪里用NoSQL比较合适？ - 未名空间MITBBS历史存档

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哪里用NoSQL比较合适？

哪里用NoSQL比较合适？# Java - 爪哇娇娃

r*s2011-12-05 08:12

1 楼

A topic for discussion:
我了解NoSQL主要用在Key/Val Pairs in large scales,
比如for storing JSON，
可是一般数据库的功能还有模型也能解决吗？
特别是做报表就不可能了，
肯定有一条线between NoSQL and DB,
有些适合NoSQL，
有些还是要Hibernate/JDBC去relational db的，
实际做过project的牛牛们说说看
这条线怎么定的？

g*g2011-12-05 08:12

2 楼

You trade performance/scalability for transaction support/integrity.

【在 r*****s 的大作中提到】

: A topic for discussion:
: 我了解NoSQL主要用在Key/Val Pairs in large scales,
: 比如for storing JSON，
: 可是一般数据库的功能还有模型也能解决吗？
: 特别是做报表就不可能了，
: 肯定有一条线between NoSQL and DB,
: 有些适合NoSQL，
: 有些还是要Hibernate/JDBC去relational db的，
: 实际做过project的牛牛们说说看
: 这条线怎么定的？

r*s2011-12-05 08:12

3 楼

这个是data model/structure很简单
而且不需要persistence或要求不高?
一般企业级的软件能用在什么地方？

【在 g*****g 的大作中提到】

: You trade performance/scalability for transaction support/integrity.

g*g2011-12-05 08:12

4 楼

Transient data, data that can be rebuilt, data that can afford
a little inconsistency, cache replacement etc.
Using it for financial transaction is calling trouble.
A hybrid SQL/NoSQL application is very common. You have to be
very careful on what you are doing.
If you have an existing application, be conservative and try
table by table.

【在 r*****s 的大作中提到】

: 这个是data model/structure很简单
: 而且不需要persistence或要求不高?
: 一般企业级的软件能用在什么地方？

r*s2011-12-05 08:12

5 楼

这Data直接从JSON到NoSQL，
没有security concern?
传统db还有dto entity呢

【在 g*****g 的大作中提到】

: Transient data, data that can be rebuilt, data that can afford
: a little inconsistency, cache replacement etc.
: Using it for financial transaction is calling trouble.
: A hybrid SQL/NoSQL application is very common. You have to be
: very careful on what you are doing.
: If you have an existing application, be conservative and try
: table by table.

g*g2011-12-05 08:12

6 楼

? I think you should have entity and DAO regardless of
SQL/NoSQL

【在 r*****s 的大作中提到】

: 这Data直接从JSON到NoSQL，
: 没有security concern?
: 传统db还有dto entity呢

r*s2011-12-05 08:12

7 楼

所以在DAO后面的？
比如MongoDB那简直就是为JSON设计的，
再把JSON转成Java Entity再转成JSON/BSON
mapping也很花时间啊，
难道实际project是这么做的？

【在 g*****g 的大作中提到】

: ? I think you should have entity and DAO regardless of
: SQL/NoSQL

g*g2011-12-05 08:12

8 楼

I never try MongoDB, we do this for Cassandra. And I
can replace the DB by simply rewriting DAOs.
I think a flexibile architecture can save you
lots of trouble in the long run. 3 layer architecture
is for decoupling, not for simplicity.

【在 r*****s 的大作中提到】

: 所以在DAO后面的？
: 比如MongoDB那简直就是为JSON设计的，
: 再把JSON转成Java Entity再转成JSON/BSON
: mapping也很花时间啊，
: 难道实际project是这么做的？

r*s2011-12-05 08:12

9 楼

thanks for sharing your exprience.
hmmmm ...
cassandra is a key/val store
while MongoDB is a "document database".
cassandra itself is like a L2 cache,
backed by hardoop?

【在 g*****g 的大作中提到】

: I never try MongoDB, we do this for Cassandra. And I
: can replace the DB by simply rewriting DAOs.
: I think a flexibile architecture can save you
: lots of trouble in the long run. 3 layer architecture
: is for decoupling, not for simplicity.

r*s2011-12-05 08:12

10 楼

再看看您的comments好像对NoSQL评价也不高啊，
我也很怕NoSQL下去遇到Dead end，
table by table哪有这个时间？
反而RDB大不了就cluster/L2 cache好了

【在 g*****g 的大作中提到】

g*g2011-12-05 08:12

11 楼

不是不高，而是说使用要谨慎，不是什么场合都合适的。
如果你需要支持大量用户，而对integrity要求不高，就可以考虑。

【在 r*****s 的大作中提到】

: 再看看您的comments好像对NoSQL评价也不高啊，
: 我也很怕NoSQL下去遇到Dead end，
: table by table哪有这个时间？
: 反而RDB大不了就cluster/L2 cache好了

r*l2011-12-05 08:12

12 楼

NoSQL != NO SQL
NoSQL == Not Only SQL
Amazon check out can use NoSQL. It's ok if you put something in cart and it
became unavailable when checking out. It's ok that some users check out OOS
item. However, the throughput under load of the website is important.
With banking application, NoSQL is tricky. If a user withdraw his only $10,
000 from ATM and within 5 minutes, he is able to withdraw another $10,000
from the counter ...

【在 r*****s 的大作中提到】

B*g2011-12-05 08:12

13 楼

NoSQL里能用SQL吗？

it
OOS

【在 r*****l 的大作中提到】

: NoSQL != NO SQL
: NoSQL == Not Only SQL
: Amazon check out can use NoSQL. It's ok if you put something in cart and it
: became unavailable when checking out. It's ok that some users check out OOS
: item. However, the throughput under load of the website is important.
: With banking application, NoSQL is tricky. If a user withdraw his only $10,
: 000 from ATM and within 5 minutes, he is able to withdraw another $10,000
: from the counter ...

g*g2011-12-05 08:12

14 楼

NoSQL is not a standard. Many implementations do have SQL
like query syntax.

【在 B*****g 的大作中提到】

: NoSQL里能用SQL吗？
:
: it
: OOS