The labels collection is of the type set<frozen<label>> , where label is a udt containing: id, name, description , all text fields.
On Sat, Nov 12, 2016 at 5:54 PM, Ali Akhtar <ali.rac...@gmail.com> wrote: > The problem isn't just the update / insert though, right? Don't frozen > entities get overwritten completely? So if I had [1] [2] being written as > updates, won't each update overwrite the set completely, so i'll end up > with either one of them instead of [1,2]? > > On Sat, Nov 12, 2016 at 5:50 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > >> Maybe you should use my Achilles mapper, which does generates UPDATE >> statements on collections and not only INSERT >> Le 12 nov. 2016 13:08, "Ali Akhtar" <ali.rac...@gmail.com> a écrit : >> >>> I am using the Java Cassandra mapper for all of these cases, so my code >>> looks like this: >>> >>> Item myItem = myaccessor.get( itemId ); >>> Mapper<Item> mapper = mappingManager.create( Item.class ); >>> >>> myItem.labels.add( newLabel ); >>> mapper.save( myItem ); >>> >>> On Sat, Nov 12, 2016 at 5:06 PM, Ali Akhtar <ali.rac...@gmail.com> >>> wrote: >>> >>>> Thanks DuyHai, I will switch to using a set. >>>> >>>> But I'm still not sure how to resolve the original question. >>>> >>>> - Original labels = [] >>>> - Request 1 arrives with label = 1, and request 2 arrives with label = 2 >>>> - Updates are sent to c* with labels = [1] and labels = [2] >>>> simultaneously. >>>> >>>> What will happen in the above case? Will it cause the labels to end up >>>> as [1,2] (what I want) or either [1] or [2]? >>>> >>>> If I use consistency level = all, will that cause it to end up with >>>> [1,2]? >>>> >>>> On Sat, Nov 12, 2016 at 4:59 PM, DuyHai Doan <doanduy...@gmail.com> >>>> wrote: >>>> >>>>> Don't use list, use set instead. If you need ordering of insertion, >>>>> use a map<timeuuid,text> where timeuuid is generated by the client to >>>>> guarantee insertion order >>>>> >>>>> When setting a new value to a list, C* will do a read-delete-write >>>>> internally e.g. read the current list, remove all its value (by a range >>>>> tombstone) and then write the new list. Please note that prepend & append >>>>> operations on list do not require this read-delete-write and thus performs >>>>> slightly better >>>>> >>>>> On Sat, Nov 12, 2016 at 11:34 AM, Ali Akhtar <ali.rac...@gmail.com> >>>>> wrote: >>>>> >>>>>> I have a table where each record contains a list<string> of labels. >>>>>> >>>>>> I have an endpoint which responds to new labels being added to a >>>>>> record by the user. >>>>>> >>>>>> Consider the following scenario: >>>>>> >>>>>> - Record X, labels = [] >>>>>> - User selects 2 labels, clicks a button, and 2 http requests are >>>>>> generated. >>>>>> - The server receives request for Label 1 and Label 2 at the same >>>>>> time. >>>>>> - Both requests see the labels as empty, add 1 label to the >>>>>> collection, and send it. >>>>>> - Record state as label 1 request sees it: [1], as label 2 sees it: >>>>>> [2] >>>>>> >>>>>> How will the above conflict be resolved? What can I do so I end up >>>>>> with [1, 2] instead of either [1] or [2] after both requests have been >>>>>> processed? >>>>>> >>>>> >>>>> >>>> >>> >
