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?
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