non-GPL free/oss embeded object/xml database? - 未名空间MITBBS历史存档

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non-GPL free/oss embeded object/xml database?

non-GPL free/oss embeded object/xml database?# Java - 爪哇娇娃

f*02008-03-09 08:03

1 楼

鱼版版主mayo公开威胁mitbbs投诉版版务说要犯戒,并继续煽动网友离开mitbbs
最后得出判决,鱼版版主mayo犯错,但不需要作出任何处罚
当年某著名网友在mitbbs开创了夸版封人的先河,现在鱼版版主mayo开创了威胁版务,犯
错不需要处罚的先河.可说是划时代,甚至可能是遗臭万年的经典啊
相关内容引用自mitbbs投诉版
链接如下: http://www.mitbbs.com/article_t/Complain/31251573.html

c*t2008-03-09 08:03

2 楼

有什么 free/oss （非 gpl）的 java object/xml database 么？打算
写个小程序看看是否能卖钱。
另外 javadb/apache derby 是否支持 variable length byte array？
thx

m*t2008-03-09 08:03

3 楼

hsqldb goes under a BSD'ish license. appache derby, of course, is under APL.
Er... can I say RTFM? 8-)

【在 c*****t 的大作中提到】

: 有什么 free/oss （非 gpl）的 java object/xml database 么？打算
: 写个小程序看看是否能卖钱。
: 另外 javadb/apache derby 是否支持 variable length byte array？
: thx

c*t2008-03-09 08:03

4 楼

APL.
Hmm, I tried to read the manual for hsqldb and it wasn't clear to
me.

【在 m******t 的大作中提到】

:
: hsqldb goes under a BSD'ish license. appache derby, of course, is under APL.
: Er... can I say RTFM? 8-)

m*t2008-03-09 08:03

5 楼

Is "variable length byte array" the same as BLOB? Or can't you emulate it
with BLOB?

【在 c*****t 的大作中提到】

:
: APL.
: Hmm, I tried to read the manual for hsqldb and it wasn't clear to
: me.

c*t2008-03-09 08:03

6 楼

It is quite different from BLOB. There are a lot of restrictions
for BLOB in terms storage, update, and indexing etc. As the result,
there are implications in terms of the performance, how it can be
utilized etc.
Basically, if I have to use BLOB, I might as well just write my
own database engine. That's how much work gets involved.
Variable length byte array is by no means a trivial feature and
it has profound impact on the database engine itself. PostgreSQL
which supports this feature (and

【在 m******t 的大作中提到】

:
: Is "variable length byte array" the same as BLOB? Or can't you emulate it
: with BLOB?

g*g2008-03-09 08:03

7 楼

It really depends on and how often you are reading/writing it.
I do use Blob to save xml configuration file, and the performance
looks fine for me.

【在 c*****t 的大作中提到】

: It is quite different from BLOB. There are a lot of restrictions
: for BLOB in terms storage, update, and indexing etc. As the result,
: there are implications in terms of the performance, how it can be
: utilized etc.
: Basically, if I have to use BLOB, I might as well just write my
: own database engine. That's how much work gets involved.
: Variable length byte array is by no means a trivial feature and
: it has profound impact on the database engine itself. PostgreSQL
: which supports this feature (and

c*t2008-03-09 08:03

8 楼

I basically need to insert / update / delete such record quite often.
Also, I might need indexing.
Sigh some good databases are either too heavy or not free.

【在 g*****g 的大作中提到】

: It really depends on and how often you are reading/writing it.
: I do use Blob to save xml configuration file, and the performance
: looks fine for me.

m*t2008-03-09 08:03

9 楼

My experience with blob/clob wasn't that bad either.
Since you are looking for java databases, I assume you want to embed one in
your application. If that's correct, do you actually care that much about
the performance difference between this and blob?
(bah, I kept mis-typing "blob" as "blog")

【在 c*****t 的大作中提到】

: I basically need to insert / update / delete such record quite often.
: Also, I might need indexing.
: Sigh some good databases are either too heavy or not free.