c*****t
发帖数: 1879 | 1 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******t
发帖数: 2416 | 2
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*****t
发帖数: 1879 | 3
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******t
发帖数: 2416 | 4
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*****t
发帖数: 1879 | 5 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*****g
发帖数: 34805 | 6 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*****t
发帖数: 1879 | 7 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******t
发帖数: 2416 | 8
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.
|
