You got me wrong perhaps.. I am already splitting the row on per user basis ofcourse, otherwise the schema wont make sense for my usage. The row contains only *reminders of a single user* sorted in chronological order. The reminder Id are stored as supercolumn name and subcolumn contain tags for that reminder.
On Wed, Feb 2, 2011 at 9:19 PM, William R Speirs <bill.spe...@gmail.com> wrote: > Any time I see/hear "a single row containing all ..." I get nervous. That > single row is going to reside on a single node. That is potentially a lot of > load (don't know the system) for that single node. Why wouldn't you split it > by at least user? If it won't be a lot of load, then why are you using > Cassandra? This seems like something that could easily fit into an > SQL/relational style DB. If it's too much data (millions of users, 100s of > millions of reminders) for a standard SQL/relational model, then it's > probably too much for a single row. > > I'm not familiar with the TTL functionality of Cassandra... sorry cannot > help/comment there, still learning :-) > > Yea, my $0.02 is that this is an effective way to leverage super columns. > > Bill- > > On 02/02/2011 10:43 AM, Aditya Narayan wrote: >> >> I think you got it exactly what I wanted to convey except for few >> things I want to clarify: >> >> I was thinking of a single row containing all reminders (& not split >> by day). History of the reminders need to be maintained for some time. >> After certain time (say 3 or 6 months) they may be deleted by ttl >> facility. >> >> "While presenting the reminders timeline to the user, latest >> supercolumns like around 50 from the start_end will be picked up and >> their subcolumns values will be compared to the Tags user has chosen >> to see and, corresponding to the filtered subcolumn values(tags), the >> rows of the reminder details would be picked up.." >> >> Is supercolumn a preferable choice for this ? Can there be a better >> schema than this ? >> >> >> -Aditya Narayan >> >> >> >> On Wed, Feb 2, 2011 at 8:54 PM, William R Speirs<bill.spe...@gmail.com> >> wrote: >>> >>> To reiterate, so I know we're both on the same page, your schema would be >>> something like this: >>> >>> - A column family (as you describe) to store the details of a reminder. >>> One >>> reminder per row. The row key would be a TimeUUID. >>> >>> - A super column family to store the reminders for each user, for each >>> day. >>> The row key would be something like: YYYYMMDD:user_id. The column names >>> would simply be the TimeUUID of the messages. The sub column names would >>> be >>> the tag names of the various reminders. >>> >>> The idea is that you would then get a slice of each row for a user, for a >>> day, that would only contain sub column names with the tags you're >>> looking >>> for? Then based upon the column names returned, you'd look-up the >>> reminders. >>> >>> That seems like a solid schema to me. >>> >>> Bill- >>> >>> On 02/02/2011 09:37 AM, Aditya Narayan wrote: >>>> >>>> Actually, I am trying to use Cassandra to display to users on my >>>> applicaiton, the list of all Reminders set by themselves for >>>> themselves, on the application. >>>> >>>> I need to store rows containing the timeline of daily Reminders put by >>>> the users, for themselves, on application. The reminders need to be >>>> presented to the user in a chronological order like a news feed. >>>> Each reminder has got certain tags associated with it(so that, at >>>> times, user may also choose to see the reminders filtered by tags in >>>> chronological order). >>>> >>>> So I thought of a schema something like this:- >>>> >>>> -Each Reminder details may be stored as separate rows in column family. >>>> -For presenting the timeline of reminders set by user to be presented >>>> to the user, the timeline row of each user would contain the Id/Key(s) >>>> (of the Reminder rows) as the supercolumn names and the subcolumns >>>> inside that supercolumns could contain the list of tags associated >>>> with particular reminder. All tags set at once during first write. The >>>> no of tags(subcolumns) will be around 8 maximum. >>>> >>>> Any comments, suggestions and feedback on the schema design are >>>> requested.. >>>> >>>> Thanks >>>> Aditya Narayan >>>> >>>> >>>> On Wed, Feb 2, 2011 at 7:49 PM, Aditya Narayan<ady...@gmail.com> >>>> wrote: >>>>> >>>>> Hey all, >>>>> >>>>> I need to store supercolumns each with around 8 subcolumns; >>>>> All the data for a supercolumn is written at once and all subcolumns >>>>> need to be retrieved together. The data in each subcolumn is not big, >>>>> it just contains keys to other rows. >>>>> >>>>> Would it be preferred to have a supercolumn family or just a standard >>>>> column family containing "all the subcolumns data serialized in single >>>>> column(s) " ? >>>>> >>>>> Thanks >>>>> Aditya Narayan >>>>> >>> >
