Okay.. so, how would you achieve the above scenario in cassandra? On Tue, Oct 11, 2016 at 3:25 AM, Peddi, Praveen <pe...@amazon.com> wrote:
> That's not just a bad idea but that's impossible. Any field that is part > of primary key is immutable. You should read up the Cassandra documentation > and understand the basics before start using it. Otherwise you could easily > abuse it inadvertently. > > Praveen > > On Oct 10, 2016, at 6:22 PM, Ali Akhtar <ali.rac...@gmail.com> wrote: > > E.g if I wanted to select * from foo where last_updated <= ? > > In this case, (I believe) last_updated will have to be a clustering key. > If the record got updated and I wanted to update last_updated accordingly, > that's a bad idea? > > :S > > On Tue, Oct 11, 2016 at 3:19 AM, Ali Akhtar <ali.rac...@gmail.com> wrote: > >> Huh - So if I wanted to search / filter by a timestamp field, and this >> timestamp needed to get updated, that won't be possible? >> >> On Tue, Oct 11, 2016 at 3:07 AM, Nicolas Douillet < >> nicolas.douil...@gmail.com> wrote: >> >>> If I correctly understand the answers, the solution to your ordering >>> question is to use clustering keys. >>> I'm agree, but I just wanted to warn you about one limitation : the >>> values of keys can't be updated, unless by using a delete and then an >>> insert. >>> (In the case of your song "example", putting the rate as a key can be >>> tricky if the value has to be frequently updated) >>> >>> >>> Le lun. 10 oct. 2016 à 22:15, Mikhail Krupitskiy < >>> mikhail.krupits...@jetbrains.com> a écrit : >>> >>>> Looks like ordering by multiple columns in Cassandra has few sides that >>>> are not obvious. >>>> I wasn’t able to find this information in the official documentation >>>> but it’s quite well described here: >>>> http://stackoverflow.com/questions/35708118/where-and-order- >>>> by-clauses-in-cassandra-cql >>>> >>>> Thanks, >>>> Mikhail >>>> >>>> On 10 Oct 2016, at 21:55, DuyHai Doan <doanduy...@gmail.com> wrote: >>>> >>>> No, we didn't record the talk this time unfortunately :( >>>> >>>> On Mon, Oct 10, 2016 at 8:17 PM, Ali Akhtar <ali.rac...@gmail.com> >>>> wrote: >>>> >>>> Really helpful slides. Is there a video to go with them? >>>> >>>> On Sun, Oct 9, 2016 at 11:48 AM, DuyHai Doan <doanduy...@gmail.com> >>>> wrote: >>>> >>>> Yes it is possible, read this: http://www.slideshare.ne >>>> t/doanduyhai/datastax-day-2016-cassandra-data-modeling-basics/24 >>>> >>>> and the following slides >>>> >>>> On Sun, Oct 9, 2016 at 2:04 AM, Ali Akhtar <ali.rac...@gmail.com> >>>> wrote: >>>> >>>> Is it possible to have multiple clustering keys in cassandra, or some >>>> other way to order by multiple columns? >>>> >>>> For example, say I have a table of songs, and each song has a rating >>>> and a date. >>>> >>>> I want to sort songs by rating first, and then with newer songs on top. >>>> >>>> So if two songs have 5 rating, and one's date is 1st Feb, the other is >>>> 2nd Feb, then I want the 2nd feb one to be sorted above the 1st feb one. >>>> >>>> Like this: >>>> >>>> Select * from songs order by rating, createdAt >>>> >>>> Is this possible? >>>> >>>> >>>> >>>> >>>> >>>> >> >
