Re: Building a News-feed that comprises posts “cre ated by user's connections” && “on the topics user is fo llowing”

I also posted this to StackOverflow, but I'll post here as well. === I'm assuming you've already studied the Twissandra example application. It's very close to what you're describing. Here are a couple of useful links: - Twissandra github project page

Re: Building a News-feed that comprises posts “cre ated by user's connections” && “on the topics user is fo llowing”

I could think of one way as follows: Initially writing to all followers about the posts from their network, by adding a column to the rows of all followers, with name as timestamp(for sort by time) and value using a JSON that contains two attributes: #PostIdKey and . At the read time, compare wit

Re: Question on timestamp

> And I notice in 0.7 roadmap there is a feature called "vector clock support" The orginal plan was to implement vector clocks for Cassandra, but Cassandra's data model actually provides at alternative solution that we'd like to start recommending. If you know that you will be experiencing unavoida

Re: anyone using Cassandra as an analytics/data warehouse?

On Wed, Jan 5, 2011 at 4:09 PM, Dave Viner wrote: > > "a Column Family with the row key being the Unix time divided by 60x60 and > a column key of... pretty much anything unique" > LogCF[hour-day-in-epoch-seconds][timeuuid] = 1 > where 'hour-day-in-epoch-seconds' is something like the first s

Re: A few quick questions to help me design a better schema..

> > 1. ) If certain columns in a row get mutated too frequently or if new > columns are added to the row frequently then does the reads of old columns > that rarely get changed is also affected ? In other words, is the > performance of reads of almost infrequently changing columns in a row where >

Building a News-feed that comprises posts “created by user's connections” && “on the topics user is follow ing”

I am working on a project of Questions & Answers website that allows a user to follow questions on certain topics from his network. I want to build user's news-feed wall that comprises of only those questions that have been posted by his connections and tagged on the topics that he is following(hi

Re: can't create a jira ticket for cassandra

Hmmm, I've never seen that when creating Jira tickets. You might try to just fill out the basic info first - Summary/Description. Then go in and edit the ticket that was created - that way you can at least create the ticket and bypass whatever error you're seeing. Weird though. On Jan 9, 201

re: can't create a jira ticket for cassandra

Hi, I tried to create a JIRA ticket for Cassandra and got the following error on submission. java.lang.NumberFormatException: For input string: "" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48) at java.lang.Long.parseLong(Long.java:431) at

A few quick questions to help me design a better schema..

1. ) If certain columns in a row get mutated too frequently or if new columns are added to the row frequently then does the reads of old columns that rarely get changed is also affected ? In other words, is the performance of reads of almost infrequently changing columns in a row where some columns

Re: Question on timestamp

> I'm very fresh to Cassandra and just read some relevant documentations. > It seems each time when a client wants to insert data to Cassandra cluster, > the client also need to assign a timestamp. Then Cassandra will keep the > timestamp and it will be used to determine which copy is the latest an

Question on timestamp

Hi all, I'm very fresh to Cassandra and just read some relevant documentations. It seems each time when a client wants to insert data to Cassandra cluster, the client also need to assign a timestamp. Then Cassandra will keep the timestamp and it will be used to determine which copy is the latest a