The use case in question was: Only accessing some columns. Even if that is not the case:
SuperColumns: 1 extra level of nesting Composite Colunns: Arbitrary levels of nesting SuperColumns: More overhead (space on disk) then using your own delimiter '_' SuperColumns: Likely going to be replaced in future c* version behind the scenes by composite columns anyway SuperColumns: Usually an afterthought for API developers, (support for them comes "later") SuperColumns: Almost always utilized incorrectly by users, users speak of '10%' performance gains after they switch away from them. There are some (a small % of cases) where SuperColumns are a better choice, but this is rare. With composites and concatenating columns they have no great purpose any more, (bad analogy coming!) like a mechanical type writer. On 12/29/11, Philippe <watche...@gmail.com> wrote: > Would you stand by that statement in case all colums inside the super > column need to be read? Why? > > Thanks > Le 28 déc. 2011 19:26, "Edward Capriolo" <edlinuxg...@gmail.com> a écrit : > >> Super columns have the same fundamental problem and perform worse in >> general. So switching from composites to super columns is NEVER a good >> idea. >> >> >> On Wed, Dec 28, 2011 at 1:19 PM, Aditya <ady...@gmail.com> wrote: >> >>> Since I have around 20 items to query, I guess making 20 queries to >>> retrieve activities by all followies on all of those 20 columns would too >>> inefficient, so to take the advantage of more efficient queries, are >>> supercolumns recommended for this case ? Anyways, in case I use >>> supercolumns, I need to retrieve the entire supercolumn at any point of >>> time & I am writing subcolumn(s) to the supercolumn at different times >>> not >>> at once. >>> >>> On Wed, Dec 28, 2011 at 8:07 PM, Edward Capriolo >>> <edlinuxg...@gmail.com>wrote: >>> >>>> You need to execute one get slice operation for each item id or if the >>>> row is not large , you can try one large get slice on the entire row and >>>> deal with the results client side. >>>> >>>> If you try method 1 When doing slices on composites you can set the >>>> start inclusive or exclusive values to get only the column you want and >>>> not >>>> some extra columns up to slice range size. >>>> >>>> >>>> On Tuesday, December 27, 2011, Aditya <ady...@gmail.com> wrote: >>>> > I need to store data of all activities by user's followies in single >>>> row. I am trying to do that making use of composite column names in a >>>> single user specific row named 'rowX'. >>>> > On any activity by a user's followie on an item, a column is stored in >>>> 'rowX'. The column has a composite type column name made up of >>>> itemId+userId (which makes it unique col. name) in rowX. (& column value >>>> contains the activity data related to that item by that followie) >>>> > >>>> > Now I want to retrieve activity by all users on a list of items. So I >>>> need to retrieve all composite columns with composite's first component >>>> matching the itemId. Is it possible to do such a query to Cassandra ? I >>>> am >>>> using Hector. >>>> >>> >>> >> >
