Selectivity should update automatically every 1000 rows, so it should never be 
wrong enough to cause problems.

-- Noel Grandin

kensystem wrote:
> First I realize my question may be naive, please accept my apologies in 
> advance.
>
> Some of the performance problems I've encountered seem to related to 
> SELECTIVITY being wrong (just needing update) for
> a given column. But when a column already has an index on it, is that index 
> not useful as a live snapshot of how
> unique the value are in it column(s)? At least where Hashmaps are concerned, 
> the size() or the Map relative to
> row-count, seems like a good way to find priority of the column/index 
> (without requiring periodic auto/manual ANALYZE,
> and which only checks first N rows).
>
> I realize b-tree indexes may be different... hence my question :-)
>
> Thanks,
> Ken
> -- 
> You received this message because you are subscribed to the Google Groups "H2 
> Database" group.
> To view this discussion on the web visit 
> https://groups.google.com/d/msg/h2-database/-/Yusy5cYjPoUJ.
> To post to this group, send email to [email protected].
> To unsubscribe from this group, send email to 
> [email protected].
> For more options, visit this group at 
> http://groups.google.com/group/h2-database?hl=en.

-- 
You received this message because you are subscribed to the Google Groups "H2 
Database" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/h2-database?hl=en.

Reply via email to