db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Kasper Nielsen <n...@kav.dk>
Subject Re: Blog response to Oracle white paper
Date Thu, 30 Nov 2006 18:09:56 GMT
David Van Couvering wrote:
> Thanks for the correction, Kasper.  Can you explain how it supports 
> queries?

The query support isn't quite on level with what SQL can offer, however, 
you can do joins such as:
EntityJoin j = new EntityJoin(myPrimaryIndex);
j.addCondition(sex, "make");
j.addCondition(age, 23);

you can also do joins on multiple secondary indexes. There is also 
support for ranged queries.


> David
> Kasper Nielsen wrote:
>> David Van Couvering wrote:
>>> Thanks, Mike, for your great comments on the white paper.  I took 
>>> those comments and added my own in a blog response:
>>> http://weblogs.java.net/blog/davidvc/archive/2006/11/oracle_benchmar_1.html 
>> Hi David,
>> Just a quick comment. I think you may want to omit or at least 
>> rephrase the following sentence:
>> -- 
>> You may not need SQL today, but think about if you may need it later. 
>> I have seen way too many projects that started with a simple key/value 
>> storage, only to add on query support, secondary indexes, and so on, 
>> as the project grows in complexity
>> -- 
>> Because Berkeley DB Java supports both secondary indexes, querying, 
>> various degrees of transaction isolation, cursor support, row level 
>> locking, etc. Its primarily the missing SQL support that sets it apart 
>> from traditional databases.
>> Other then that, great post.
>> Cheers
>>   Kasper

View raw message