cassandra

Cassandra or MySQL/PostgreSQL?

Hi! I have huge database (kinda wordnet) and want to know if it's easier to use Cassandra instead of MySQL|PostrgreSQL All my life I was using MySQL and PostrgreSQL and I could easily think in terms of relational algebra, but several weeks ago I learned about cassandra and that it's used in Facebook and Twitter. Is it more convenient? ...

Are column families within a single keyspace related in any way?

What's the difference between having keyspace Foo and column families A and B in it vs. having two keyspaces FooA and FooB with one column family in each? API make it look as if these two were pretty much equivalent. As a bonus question, how do supercolumns fit into this picture? ...

Cassandra and asp.net (C#)

I am interested to create portal on cassandra services, since I faced some performance and scale issues starting from 1 million of records. Definitely, it could be solved, but I am interested on other options. My main issues is cost of updating all necessary indexes, to make reading fast. First, is cassandra is good way for asp.net pr...

What is the equivalent for pycassa ColumnFamily.get_range() with Lazyboy?

I think everything is in the question. I'm looking for the Lazyboy equivalent for Pycassa ColumnFamily.get_range() -- with features like column_start, column_finish et column_count --. Thanks. ...

Fetching Cassandra row keys

Assume a Cassandra datastore with 20 rows, with row keys named "r1" .. "r20". Questions: How do I fetch the row keys of the first ten rows (r1 to r10)? How do I fetch the row keys of the next ten rows (r11 to r20)? I'm looking for the Cassandra analogy to: SELECT row_key FROM table LIMIT 0, 10; SELECT row_key FROM table LIMIT 10, 1...

The usage of Cassandra's internal keyspace "system"

The default Cassandra systems keyspace system is present in all Cassandra installations. Judging from the output of the describe keyspace command the keyspace is used partly for "persistent metadata for the local node" (LocationInfo) and partly for "hinted handoff data". What persistent metadata for the local node is stored in system/...

Querying a Cassandra column family for rows that have not been updated in X days

I'm moving an existing MySQL based application over to Cassandra. So far finding the equivalent Cassandra data model has been quite easy, but I've stumbled on the following problem for which I'd appreciate some input: Consider a MySQL table holding millions of entities: CREATE TABLE entities ( id INT AUTO_INCREMENT NOT NULL, entity...

Cassandra database, which python interface?

Hi, I'm going to write the web portal using Cassandra databases. Can you advise me which python interface to use? thrift, lazygal or pycassa? Are there any benefits to use more complicated thrift then cleaner pycassa? What about performace - is the same (all of them are just the layer)? Thanks for any advice. ...

How to get a list of items when using cassandra

When using a nosql type datastore like Cassandra, how would you return a result set based on a column? e.g. SELECT * FROM Articles WHERE category='blah' ORDER BY datetime DESC is this something that you would store in a sql db and then pull the data from cassandra? Or can cassandra handle this type of query? (assuming millions of ro...

Cassandra hot keyspace structure change

Hello. I'm currently running a 12-node Cassandra cluster storing 4TB of data, with a replication factor set to 3. For the needs of an application update, we need to change the configuration of our keyspace, and we'd like to avoid any downtime if possible. I read on a mailing list that the best way to do it is to: Kill cassandra proce...

Can sphinx be used over cassandra?

I am planning to build a cassandra store system and also I need a full-text(Chinese) system too. Can sphinx be used on cassandra? (sphinx supports xml format but I am not going to use it, cause it is slow and much of time are spent on xml parsing). Or you can share your experiences if you have ever built a full-text searching system over...

What are the alternative ways to model M:M relations in Cassandra?

Consider a M:M relation that needs to be represented in a Cassandra data store. What M:M modeling options are available? For each alternative, when is it to prefer? What M:M modeling choices have you made in your Cassandra powered projects? ...

What is an SSTable?

In BigTable/GFS and Cassandra terminology, what is the definition of a SSTable? ...

MySQL app with Cassandra in mind

I am planning to make a web app which will eventually use Cassandra. But now that I don't have it and don't have server(s) to run it from, I'd like to start by using MySQL. The question is, is it possible to structure data and queries in such a way that it would be fairly easy to later port it to Cassandra? Main idea, I guess, would be...

Cassandra instead of MySQL for social networking app

I am in the middle of building a new app which will have very similar features to Facebook and although obviously it wont ever have to deal with the likes of 400,000,000 million users it will still be used by a substantial user base and most of them will demand it run very very quickly. I have extensive experience with MySQL but a socia...

Cassandra datastore client in Go language

Is it possible to write client for Cassandra datastore in Go language? ...

Cassandra or mysql 5 ? Which will be good for future ?

Should I use cassandra in 100,000 users project ? In mysql 5 have full text search and partition table. I'm starting to make Question and answer system like stackoverflow with CodeIgniter. It's move from vbulletin to new system. In old vbulletin have around 100,000 users and total post is around 80,000. In next 3 or 4 year, users and pos...

In Cassandra terminology, what is TimeUUID?

In Cassandra terminology, what is TimeUUID and when is it used? ...

Searches (and general querying) with HBase and/or Cassandra (best practices?)

I have User model object with quite few fields (properties, if you wish) in it. Say "firstname", "lastname", "city" and "year-of-birth". Each user also gets "unique id". I want to be able to search by them. How do I do that properly? How to do that at all? My understanding (will work for pretty much any key-value storage -- first goes ...

When NOT to use Cassandra?

There has been a lot of talk related to Cassandra lately. Twitter, Digg, Facebook, etc all use it. When does it make sense to: use Cassandra, not use Cassandra, and use a RDMS instead of Cassandra. ...