"they require knowing the key in advance in order to look up the counters"
--> Wrong Imagine your table partition_key uuid, first_map map<int, counter>, second_map map<int, counter> With my proposed data model: SELECT first_map FROM table would translate to SELECT map_key, count FROM my_counters_map WHERE partition_key = xxx AND map_name = 'first_map'; On Wed, Nov 9, 2016 at 1:52 PM, Ali Akhtar <ali.rac...@gmail.com> wrote: > The only issue with the last 2 solutions is, they require knowing the key > in advance in order to look up the counters. > > The keys however are dynamic in my case. > > On Wed, Nov 9, 2016 at 5:47 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > >> "Is there a way to do this in c* which doesn't require creating 1 table >> per type of map<int, counter> that i need?" >> >> You're lucky, it's possible with some tricks >> >> >> CREATE TABLE my_counters_map ( >> partition_key id uuid, >> map_name text, >> map_key int, >> count counter, >> PRIMARY KEY ((id), map_name, map_key) >> ); >> >> This table can be seen as: >> >> Map <partition_key, SortedMap<map_name, SortddMap<map_key, counter>>> >> >> The couple (map_key, counter) simulates your map >> >> The clustering column map_name allows you to have multiple maps of >> counters for a single partition_key >> >> >> >> On Wed, Nov 9, 2016 at 1:32 PM, Vladimir Yudovin <vla...@winguzone.com> >> wrote: >> >>> Unfortunately it's impossible nor to use counters inside collections >>> neither mix them with other non-counter columns : >>> >>> CREATE TABLE cnt (id int PRIMARY KEY , cntmap MAP<int,counter>); >>> InvalidRequest: Error from server: code=2200 [Invalid query] >>> message="Counters are not allowed inside collections: map<int, counter>" >>> >>> CREATE TABLE cnt (id int PRIMARY KEY , cnt1 counter, txt text); >>> InvalidRequest: Error from server: code=2200 [Invalid query] >>> message="Cannot mix counter and non counter columns in the same table" >>> >>> >>> >Is there a way to do this in c* which doesn't require creating 1 table >>> per type of map<int, counter> that i need? >>> But you don't need to create separate table per each counter, just use >>> one row per counter: >>> >>> CREATE TABLE cnt (id int PRIMARY KEY , value counter); >>> >>> Best regards, Vladimir Yudovin, >>> >>> *Winguzone <https://winguzone.com?from=list> - Hosted Cloud >>> CassandraLaunch your cluster in minutes.* >>> >>> >>> ---- On Wed, 09 Nov 2016 07:17:53 -0500*Ali Akhtar >>> <ali.rac...@gmail.com <ali.rac...@gmail.com>>* wrote ---- >>> >>> I have a use-case where I need to have a dynamic number of counters. >>> >>> The easiest way to do this would be to have a map<int, counter> where >>> the int is the key, and the counter is the value which is incremented / >>> decremented. E.g if something related to 5 happened, then i'd get the >>> counter for 5 and increment / decrement it. >>> >>> I also need to have multiple map<int, counter>s of this type, where each >>> int is a key referring to something different. >>> >>> Is there a way to do this in c* which doesn't require creating 1 table >>> per type of map<int, counter> that i need? >>> >>> >>> >> >
