Re: 8.4 release notes proof reading 1/2 - Mailing list pgsql-hackers

On Mar 27, 2009, at 6:40 PM, Bruce Momjian wrote:

> Thanks, text updated:
>
>       While semi-joins merely replace existing IN joins, anti-joins
>       are a new capability for NOT EXISTS clauses (Tom) This improves
>       optimization possibilities.

I'm not enough of a relational algebra geek to really understand what  
that means. Will there be a link or something to some documentation or  
even, *gasp*, a blog entry explaining what this means and why it's  
important?

Thanks,

David