On Sat, Mar 17, 2012 at 8:50 AM, HuangQi <huangqiyx@gmail.com> wrote:
> I'm quite glad if you could offer me some advices. Thanks a lot for your
> help!
Thank you for your interest! However, I am a little confused precisely
what you are thinking about implementing. Are there particular access
methods or operators that you think are useful in this problem space,
or changes to the planner?
As long as you are soliciting for suggestions, I'll make one...
One that bites me (and my organization) all the time is the lack of
the access method skip scan (also called "loose index scan"). It's a
killer for append-mostly tables that track a much smaller number of
entities than the number of records in the table, and we have a
grotesque hack to do it right now. In the more "social" space the
problem reappears in the form of newsfeeds, so I think that work would
have good impact across a nice spectrum of users.
Another skip-related feature that would be very nice is the
SQL-standard TABLESAMPLE feature. I wonder if the notion of a
"SkipKind" could be taught to the executor that would provide cohesion
of implementation for most feature that involve skipping a lot of the
rows in a table while continuing a scan.
--
fdr