Hi, > I have been experimenting with mapDB but having some problems
As far as I understand, MapDB should support it as well. What kind of problems did you run into (just curious)? > One requirement of my project requires importing of the large Geonames database (www.geonames.org) Thats very interesting! I guess using compression should help a lot in this case, and possibly using a larger page size - specially if you have more reads than writes. Regards, Thomas On Thu, Aug 29, 2013 at 3:04 PM, Paul F Fraser <[email protected]> wrote: > On 29/08/13 22:45, Thomas Mueller wrote: > > Hi, > > Why do you want to know, do you want to build you own secondary index > and use MVStore directly? > > > yes. > > I have been experimenting with mapDB but having some problems. Tried the > same approach with MVStore and it worked without problems. One requirement > of my project requires importing of the large Geonames database ( www.* > geonames*.org) which ends up as a db file well in excess of 1G. > I also think the single file will be an advantage in my project. > > > For the MVTableEngine, currently, the key of an index is a "Value", > actually a "ValueArray". The last value of the ValueArray is the row id > (which matches the primary key for bigint or int primary keys). See also > the MVSecondaryIndex class. But this is an implementation detail, and might > change later. > > > Is it practical with MVStore to use a single key with a list as the value > containing the row id's for a simple single column index? > > > Regards, > Thomas > > > > On Thu, Aug 29, 2013 at 2:34 PM, Paul F Fraser <[email protected]>wrote: > >> The available info on non-unique keys in MVStore states that the plan is >> to use map key as index columns (combined). One of the index columns is >> always the row Id. >> >> When the key is put to the map, is the key kept as an array or are the >> entries in the array concatenated somehow? >> >> How is the set of keys matching the desired index value retrieved? >> >> regards >> >> Paul Fraser >> >> -- >> You received this message because you are subscribed to the Google Groups >> "H2 Database" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/h2-database. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/h2-database. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/h2-database. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/groups/opt_out.
