[elephant-devel] QDBM Support

Thu Feb 14 07:16:28 UTC 2008

Thanks for the detailed suggestions.

I haven't thought about Postgres, but your suggestion sounds good. Does 
Postgres require any admin-type task by end users of my application? I hope 
not, because my intended audience is medical Doctors!

I am in contact with Oracle India regarding the license and they have 
confirmed that I have to pay royalties. Although the royalty appears quite 
reasonable, looks like I have to be an "Oracle Partner" to distribute BDB 
under this licensing clause. There is an annual fee to be an OPN, which 
equals about 100 license royalty payments per year!

Before I bought LispWorks I was keen to use Allegro CL/Allegro Cache, but 
found that the royalties there are astronomical, so decided to switch 
loyalty to LW. Let us see how this goes.

For a product that cannot cost more than $500, and might not sell in huge 
numbers, this seems like too much trouble!

Thanks for your advice.
Regards,
Rangarajan
----- Original Message ----- 
From: "Robert L. Read" <read at robertlread.net>
To: "Elephant bugs and development" <elephant-devel at common-lisp.net>
Sent: Thursday, February 14, 2008 11:01 AM
Subject: Re: [elephant-devel] QDBM Support

> On Thu, 2008-02-14 at 10:35 +0530, Rangarajan Krishnamoorthy wrote:
>> Robert,
>> I am the one who started this thread, so let me clarify.
>>
>> The background: I am starting to work on a .NET-based application (for
>> Windows platforms) that might benefit by Lisp integration. I purchased
>> Lispworks Enterprise in this context. When I searched for a lisp 
>> persistence
>> library, I was told to consider Elephant. I tried it and it seems to work
>> fine for me. Elephant documentation advises that BDB is the best 
>> performing
>> backend among the backends it supports. But it appears that I cannot just
>> "buy" BDB by opting for a one-time initial payment. I have to pay runtime
>> royalties. This is different from other libraries that I have used so 
>> far.
>> Although there may be legitimate reasons why Oracle does it this way, I 
>> am
>> more comfortable with one-time payment. So the problem I am facing is 
>> that I
>> would love to use Elephant in my work, but BDB's licensing is the 
>> concern. I
>> found out that QDBM is another popular DB implementation which does not 
>> have
>> this licensing issue, so posted the question to this list. It is not just
>> that QDBM outperforms BDB (I don't know this). Please note that I am not
>> against paying for the library that I use, but just that I am not in 
>> favor
>> of royalties.
>
> Thanks for the clarification --- I got tangled in the thread.
>
> However, this allows me to rephrase my question:  Can you consider using
> the postmodern backend (which is an interface to the PostGres database)?
>
> PostGres is free.  The Postmodern backend is probably 3 to 10 times
> slower than BDB, and might be even worse in some circumstances.
> However, it is entirely possible that 10 times very fast is still fast
> enough for whatever operation you intend.
>
> It is unfortunate that to test this you will have to install PostGres
> and do a very, very small amount of db administration on PostGres in
> order to execute Elephant against it.  With experience this should only
> take a few hours.
>
> I share your attitude toward royalties in this matter, which is mainly
> the reason I wrote the CL-SQL-based backend.
>
> I know only what you have stated about your application, but one
> possibility, if you have no better alternative to Elephant, is to use
> the postmodern backend now, during your development, and be prepared to
> either switch to BDB by paying for it later, or to hope for (and perhaps
> help) an effort to either implement QDBM or a LISP-native backend.
>
> Allow me to ask if you have really carefully considered the BDB license:
>
> http://www.oracle.com/technology/software/products/berkeley-db/htdocs/oslicense.html
>
> ...and concluded that you would have to pay a runtime royalty for your
> specific application?
>
> (As an aside:  I have not studied the other persistence solutions
> deeply.  I suspect that using CL-SQL directly (not through Elephant) is
> one of the most common and well-tested mechanisms.  This is an
> Object-Relational Mapper (ORM) similar to Hibernate or Ibatis (although
> a bit less evolved, I think.)  This approach would require you to do a
> great deal more work than Elephant does, since you have to create tables
> and consciously map your classes into those tables and be prepared to
> deal with schema evolution when you change the design of your object
> space.  I think Elephant is much more convenient, but using CL-SQL
> directly is an option.)
>
>
>
>
>
>
>>
>> Coming to your suggestion that it would be wise to build a very simple,
>> native lisp backend without the "frills", I am for it!
>>
>> Regards,
>> Rangarajan
>>
>> ----- Original Message ----- 
>> From: "Robert L. Read" <read at robertlread.net>
>> To: "Elephant bugs and development" <elephant-devel at common-lisp.net>
>> Sent: Thursday, February 14, 2008 9:38 AM
>> Subject: Re: [elephant-devel] QDBM Support
>>
>>
>> > On Wed, 2008-02-13 at 10:41 -0500, Ian Eslick wrote:
>> >> The answer to all of this, I think, is having a native lisp version
>> >> that has BDB's performance and no licensing restrictions.  Then
>> >> supporting the other two becomes: Postmodern for a higher degree of
>> >> reliability as well as for distributed systems and BDB for legacy
>> >> reasons.
>> >>
>> >> I have a pretty good idea in my head of what an all-lisp backend
>> >> requires and having one would lay to rest all of these discussions
>> >> of
>> >> bringing up "yet another backend".  Edi Weitz and I discussed
>> >> collaborating on this, but unfortunately he had some other projects
>> >> that took priority.
>> >>
>> >> Is there a small critical mass of people out there that care enough
>> >> about this that they'd be willing to contribute to such a project?
>> >> I
>> >> don't have the time to do it on my own, but if we broke it up into
>> >> small projects over the next handful of months, I don't think it's a
>> >> ton of work.  I can put in a solid chunk of integration work in mid
>> >> to
>> >> late April.
>> >>
>> >
>> > I completely agree with Ian about the value of a LISP-native backend.
>> >
>> > However, I can not personally offer to help with this.  I have in fact
>> > abandoned my business plans for the time being and taken a normal job.
>> > Moreover, since I did the "schema evolution" system that we used in the
>> > Java application for Hire.com a while back, I feel more comfortable
>> > working on that than on the LISP native backend, although I think both
>> > are wonderful and challenging problems.
>> >
>> > The excellent set of automated tests produced by the original authors 
>> > of
>> > Elephant (Andrew Blumberg and Ben Lee) and strengthened by Ian and
>> > myself and others since then remain the greatest asset in undertaking
>> > the LISP-Native backend.
>> >
>> > I know that many of you understand most of the technical challenges in
>> > bringing up a Native LISP backend better than I do.  However, let me 
>> > ask
>> > the question that my acquaintance Kent Beck always asks:
>> >
>> > What is the simplest thing that could possible work?
>> >
>> > By which I mean, is there any value in making a very simple LISP native
>> > backend?  Forget locking, transactions, efficiency, and all that other
>> > ocean-boiling stuff that we all know will be needed for an enterprise
>> > application.  Can anybody build a Native-Lisp backend in a weekend?
>> >
>> > If so, we would have an excellent "spike" solution that would inform
>> > further efforts, and furthermore we would have an out-of-the-box
>> > solution for demoing Elephant that would require ZERO additional
>> > software installations.  This would be very useful, even if there are
>> > performance and reliability limits to that backend.
>> >
>> >
>> > _______________________________________________
>> > elephant-devel site list
>> > elephant-devel at common-lisp.net
>> > http://common-lisp.net/mailman/listinfo/elephant-devel
>>
>>
>> _______________________________________________
>> elephant-devel site list
>> elephant-devel at common-lisp.net
>> http://common-lisp.net/mailman/listinfo/elephant-devel
>
> _______________________________________________
> elephant-devel site list
> elephant-devel at common-lisp.net
> http://common-lisp.net/mailman/listinfo/elephant-devel 