>The keys however are dynamic in my case.
Why is it problem for you? As you said "if something related to 5 happened,
then i'd get the counter for 5 and increment / decrement it."
So do "UPDATE cnt SET value = value + SOMETHING where id = 5;"
If counter for event 5 exists it will be changed, if not - created set to
initial value.
Best regards, Vladimir Yudovin,
Winguzone - Hosted Cloud Cassandra
Launch your cluster in minutes.
---- On Wed, 09 Nov 2016 07:52:29 -0500Ali 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 - Hosted Cloud Cassandra
Launch your cluster in minutes.
---- On Wed, 09 Nov 2016 07:17:53 -0500Ali Akhtar <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?
