Re: : Tracking Full Table Scans

Thanks Kevin !!

I will have a look at the source tree.

Regards
VB

On Tue, Sep 27, 2011 at 10:45 PM, Kevin Grittner <
Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:

> Venkat Balaji <venkat(dot)balaji(at)verse(dot)in> wrote:
>
> > I would like to know the difference between "n_tup_upd" and
> > "n_tup_hot_upd".
>
> A HOT update is used when none of the updated columns are used in an
> index and there is room for the new tuple (version of the row) on
> the same page as the old tuple. This is faster for a number of
> reasons, and cleanup of the old tuple is a little different.
>
> If you want the gory implementation details, take a look at this
> file in the source tree:
>
> src/backend/access/heap/README.HOT
>
> -Kevin
>