[bind10-dev] Blog comment from BDB developer

[Shane Kerr]

Danny,

On Tue, 2010-07-13 at 07:46 -0400, Danny Mayer wrote:
> On 7/12/2010 10:45 PM, zhanglikun wrote:
> > Danny wrote:
> >> you have no idea how bad that would be from a DB performance point
> >>of view. You *really* don't want to do this.
> > 
> >> I've never heard of something like that in Java and I do quite a  
> >> lot of Java programming with databases these days. I doubt that 
> >> this is true.
> >> Databases either find the records requested or not. There's no in 
> >> between. You are better off getting the resultset and processing 
> >> the records for what you need.
> > 
> > BDB have one native flag ' DB_SET_RANGE ' supporting to get records
> > in between. see the following discussions.
> > 
> >> Likun,
> 
> Yes I read that. The implications of this is that you are going to be
> limiting bind10 to only use BDB since no other DB supports it. That's
> okay if you are going to be making that as a final decision, but then
> that needs to be explicitly stated.

I'm not sure exactly what you mean. SQL provides us this functionality
today by using '<' operators. Here is how we find the covering NSEC
record:

    SELECT name FROM records 
    WHERE zone_id=?1 AND rdtype = 'NSEC' AND rname < $2 
    ORDER BY rname DESC LIMIT 1

(Pardon the SQLite "LIMIT" extension there, but that is pretty common in
SQL databases, and can be synthesized if necessary in other SQL
variants.)

--
Shane