wondering if it provides some kind of counters or sequence number generator? i want to use the sequence for minor keys. the use case is, i have bunch log data that i collected, i want to store them using some kind of auto-incremented minor keys.
is there any append to value feature.. lets say i have an existing kv, now i collected more data for the key, i just want to append the value to the existing value. i don't want to fetch the whole value, append them in application layer and send the updated value to kvstore.
Neither of these features are in the product.
It is possible to implement your own counter using a single kv pair that stores the last used value. When you update it, you'll need to use putIfVersion along with a retry loop to support concurrent updates. And you should increment the value by more than 1 -- say by 100 -- and dole out the 100 values on the client side before updating the counter again; this avoid updating the counter for every insert operation.
If you find yourself wanting to append to a value, you should consider multiple kv pairs instead, with keys designed such that they can be queried using a multi-get operation. In almost all cases the data store performs better when multiple values are inserted, rather than updating a single kv pair and appending to its value.