Hi Vladimir, As far as I know, Redis' SortedSet is not shared. Is this correct? Is it even possible to support similar functionality for a partitioned dataset?
-Val On Fri, Sep 4, 2020 at 8:58 AM Denis Magda <dma...@apache.org> wrote: > Hi Vladimir, > > Usually, LSM-storage engines serve the range searches the best (Cassandra > is one of the examples). The SortedSet of Redis is one of the typical > components you can find in LSM-engines. > > Presently, Ignite neither supports an LSM store nor a SortedSet data > structure. However, the range searches with Ignite still have O(log(n)) > complexity, it just takes more steps for the B-tree to collect all the > records of a range. > > - > Denis > > > On Fri, Sep 4, 2020 at 3:26 AM Vladimir Pligin <vova199...@yandex.ru> > wrote: > > > Hi Igniters, > > > > It seems that it's not possible to implement effective leader-board with > > the > > current Ignite indexes. > > Leader-board stores a score and an id of a player of some game. Score is > > indexed. One of the possible requests to that data structure is to get > some > > range of scores based on their rank (it's effectively a number of a > row). I > > suppose it's required for pagination. For example Redis has an index > > (https://redis.io/topics/data-types#sorted-sets) that can be scanned > > (https://redis.io/commands/zrange) to a particular line with O(log(n)) > > complexity. As far as I know it's node-local. Correct me if I'm wrong but > > in > > Ignite we scan an index until we find a row corresponding to a > limit/offset > > clause. It looks like a linear complexity. I suppose it could be possible > > to > > implement it for REPLICATED caches and local queries. But it's really > > difficult for me to estimate the efforts. By the way it would be useful > for > > analytical tools, most of them paginate. So what do you think is it > > possible > > to make that happen in Ignite and do we need it at all? Ignite 3.0 maybe? > > > > > > > > -- > > Sent from: http://apache-ignite-developers.2346864.n4.nabble.com/ > > >
