Hi Ah, yes, I see what you are saying. I'm afraid on-disk b-tree indexes don't work that way. They have an entry for every row in the table, so index.size() == table.size().
-- Noel Grandin kensystem wrote: > Hi Noel, thank you for your reply! Well, I was actually thinking (asking) if > calling size() on the index would be > better, since: > > a) the selectivity doesnt need to repeatedly-evaluated (separate thread, or > blocking as case may be) and consume CPU > when (if) size can just be called instead. > > b) The first N rows that the selectivity-checks could (I imagine) be > less-than an ideal sampling, for example when > importing millions of already-sorted geodata (where the first N rows might > have thousands of same values) > > Looking at the size() impl in java.util.TreeMap (which I suspect is not the > same impl as H2's), it's just a return > value for the int size field. > > Hope this is clearer, > 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/-/qSNV3FEY-MMJ. > 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.
