Re: Reduce maximum error in tuples estimation after vacuum.

Sorry, I made an mistake.

"Kyotaro HORIGUCHI" <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>:

> Overall algorithm could be illistrated as below,
>
> - summing up used bytes, max offnum(PageGetMaxOffsetNumber),

Not "max" offnum, the number of linp's used after page vacuum.

> maximum free bytes for tuple data , and free bytes after page
> vacuum through all scanned pages.
>
> - summing up free bytes informed by FSM through all skipped
> pages.
>
> - Calculate mean tuple length from the overall used bytes and
> sum of max offnums, and scanned pages.

Here also is the same. not sum of max offnum but total of used
entrre(linp)s.

> - Guess tuple density in skipped pages using overall free bytes
> from FSM and the mean tuple length calculated above.
>
> - Finally, feed estimated number of the live tuples BEFORE
> vacuum into vac_estimate_reltuples.

regards,

--
Kyotaro Horiguchi