On Thu, Aug 4, 2016 at 06:03:34PM +0100, Simon Riggs wrote:
> On 4 August 2016 at 02:13, Bruce Momjian <bruce@momjian.us> wrote:
>
> > How do plan to clear the bitmask so it, over time, doesn't end up being
> > all-set?
>
> I don't have a plan, though thoughts welcome.
>
> Similar situation that our current indexes don't recover from bloat, a
> situation made worse by non-HOT updates.
>
> So, we have a choice of which disadvantage to accept.
>
>
> > Also, why not use this bitmap for all indexes, not just update chains?
>
> I don't understand where you get this update chains thing from.
>
> The bitmap can apply to multiple tuples on one page, which is described.
I am asking if we could use this idea for all rows on a page, not just
HOT updated, e.g. we have five rows that have col1=4 in an index --- why
not just use on index pointer for all of them, with a bitmap to point to
the possible matches?
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com
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