Re: text_position worst case runtime

On Thu, May 18, 2006 at 06:49:38PM -0700, Mark Dilger wrote:
> > I would think that the worst-case times would be fairly improbable.
> > I'm disinclined to push something as complicated as Boyer-Moore matching
> > into this function without considerable evidence that it's a performance
> > bottleneck for real applications.
> 
> A common approach in biological data applications is to store nucleic and amino
> acid sequences as text in a relational database.  The smaller alphabet sizes and
> the tendency for redundancy in these sequences increases the likelihood of a
> performance problem.  I have solved this problem by writing my own data types
> with their own functions for sequence comparison and alignment, and I used
> boyer-moore for some of that work.  Whether the same technique should be used
> for the text and varchar types was unclear to me, hence the question.

Perhaps it would be best to add a seperate set of functions that use
boyer-moore, and reference them in appropriate places in the
documentation. Unless someone has a better idea on how we can find out
what people are actually doing in the field...
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461