@DuyHai Yes, that's another case, the "entity" model used in rdbms. But I need rows together to work with them (indexing etc).
@sfespace The map is needed when you have a dynamic schema. I don't have a dynamic schema (may have, and will use the map if I do). I just have thousands of schemas. One user needs 10 integers, while another user needs 20 booleans, and another needs 30 integers, or a combination of them all. On Thu, Sep 15, 2016 at 7:46 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > "Another possible alternative is to use a single map column" > > --> how do you manage the different types then ? Because maps in Cassandra > are strongly typed > > Unless you set the type of map value to blob, in this case you might as > well store all the object as a single blob column > > On Thu, Sep 15, 2016 at 6:13 PM, sfesc...@gmail.com <sfesc...@gmail.com> > wrote: > >> Another possible alternative is to use a single map column. >> >> >> On Thu, Sep 15, 2016 at 7:19 AM Dorian Hoxha <dorian.ho...@gmail.com> >> wrote: >> >>> Since I will only have 1 table with that many columns, and the other >>> tables will be "normal" tables with max 30 columns, and the memory of 2K >>> columns won't be that big, I'm gonna guess I'll be fine. >>> >>> The data model is too dynamic, the alternative would be to create a >>> table for each user which will have even more overhead since the number of >>> users is in the several thousands/millions. >>> >>> >>> On Thu, Sep 15, 2016 at 3:04 PM, DuyHai Doan <doanduy...@gmail.com> >>> wrote: >>> >>>> There is no real limit in term of number of columns in a table, I would >>>> say that the impact of having a lot of columns is the amount of meta data >>>> C* needs to keep in memory for encoding/decoding each row. >>>> >>>> Now, if you have a table with 1000+ columns, the problem is probably >>>> your data model... >>>> >>>> On Thu, Sep 15, 2016 at 2:59 PM, Dorian Hoxha <dorian.ho...@gmail.com> >>>> wrote: >>>> >>>>> Is there alot of overhead with having a big number of columns in a >>>>> table ? Not unbounded, but say, would 2000 be a problem(I think that's the >>>>> maximum I'll need) ? >>>>> >>>>> Thank You >>>>> >>>> >>>> >>> >
