Comments for Sodeso http://www.sodeso.nl Software Development Solutions Thu, 26 Aug 2010 12:13:22 +0000 http://wordpress.org/?v=2.9.2 hourly 1 Comment on Installing and using Apache Cassandra With Java Part 3 (Data model 2) by Ronald Mathieshttp://www.sodeso.nl/?p=207&cpage=1#comment-1020 Ronald Mathies Thu, 26 Aug 2010 12:13:22 +0000 http://www.sodeso.nl/?p=207#comment-1020 Retrieving all data from a ColumnFamily can be done by using the KeyRange class. Normally you would specify a starting key and an end key but they are not required. However you do need to specify a count as to how many rows you want to retrieve.You need to keep one thing in mind, until Cassandra 0.7 (and possibly the first beta's 0.7) you cannot retrieve more data that can fit in memory at a time.About the sorting, Cassandra stores it's data in a sorting manner, besides the default sorting types you can also create a custom sorting class. More information about this can be found here:<a href="http://www.sodeso.nl/?p=421" rel="nofollow">Creating custom sorting types for Apache Cassandra</a>Hope this answers your questions... Retrieving all data from a ColumnFamily can be done by using the KeyRange class. Normally you would specify a starting key and an end key but they are not required. However you do need to specify a count as to how many rows you want to retrieve.

You need to keep one thing in mind, until Cassandra 0.7 (and possibly the first beta’s 0.7) you cannot retrieve more data that can fit in memory at a time.

About the sorting, Cassandra stores it’s data in a sorting manner, besides the default sorting types you can also create a custom sorting class. More information about this can be found here:

Creating custom sorting types for Apache Cassandra

Hope this answers your questions…

]]> Comment on Installing and using Apache Cassandra With Java Part 3 (Data model 2) by Sekharhttp://www.sodeso.nl/?p=207&cpage=1#comment-1019 Sekhar Thu, 26 Aug 2010 11:57:09 +0000 http://www.sodeso.nl/?p=207#comment-1019 HiI am a new Bie of Cassandra DB, say suppose i want to load all the records from a table, in the cassandra terminilogy how to load all the key values from a columnfamily, if you dont know the keys values.and one more thing any sorting kind of thing we can't done at db level right, all has take care in the application only, so more burden in the application, any alternatives for this .....Thanks in Advance.... :) Hi

I am a new Bie of Cassandra DB, say suppose i want to load all the records from a table, in the cassandra terminilogy how to load all the key values from a columnfamily, if you dont know the keys values.

and one more thing any sorting kind of thing we can’t done at db level right, all has take care in the application only, so more burden in the application, any alternatives for this …..

Thanks in Advance…. :)

]]> Comment on Sparrow 0.9: New Xcode Templates by Ronald Mathieshttp://www.sodeso.nl/?p=1225&cpage=1#comment-1016 Ronald Mathies Mon, 23 Aug 2010 19:08:20 +0000 http://www.sodeso.nl/?p=1225#comment-1016 Oke, i've taken a look. I have created a new project for all combinations, iPhone, iPad and universal.. i cannot see any problems with the templates, i just create them and i start them directly. Are you still experiencing the described problems? Oke, i’ve taken a look. I have created a new project for all combinations, iPhone, iPad and universal.. i cannot see any problems with the templates, i just create them and i start them directly. Are you still experiencing the described problems?

]]> Comment on Close All Tabs by Al fondo que hay lugar / Extensiones para Safari 5 « AlephBloghttp://www.sodeso.nl/?page_id=1202&cpage=1#comment-1015 Al fondo que hay lugar / Extensiones para Safari 5 « AlephBlog Mon, 23 Aug 2010 16:45:21 +0000 http://www.sodeso.nl/?page_id=1202#comment-1015 [...] cerrar todas las pestañas pero no quieres cerrar el navegador? Close All Tabs nos permite cerrar todas las pestañas que tengamos abiertas menos la pestaña que estemos [...] [...] cerrar todas las pestañas pero no quieres cerrar el navegador? Close All Tabs nos permite cerrar todas las pestañas que tengamos abiertas menos la pestaña que estemos [...]

]]> Comment on Sparrow 0.9: New Xcode Templates by Ronald Mathieshttp://www.sodeso.nl/?p=1225&cpage=1#comment-1013 Ronald Mathies Mon, 23 Aug 2010 06:27:01 +0000 http://www.sodeso.nl/?p=1225#comment-1013 I'll have a look at this and update the template as soon as i, thanks for reporting this problem. I’ll have a look at this and update the template as soon as i, thanks for reporting this problem.

]]> Comment on Close All Tabs by Más extensiones para Safari 5 en AppleWeblog (Mac OS X)http://www.sodeso.nl/?page_id=1202&cpage=1#comment-1009 Más extensiones para Safari 5 en AppleWeblog (Mac OS X) Sun, 22 Aug 2010 14:29:34 +0000 http://www.sodeso.nl/?page_id=1202#comment-1009 [...] de Apple.Close All Tabs¿Quieres cerrar todas las pestañas pero no quieres cerrar el navegador? Close All Tabs nos permite cerrar todas las pestañas que tengamos abiertas menos la pestaña que estemos [...] [...] de Apple.Close All Tabs¿Quieres cerrar todas las pestañas pero no quieres cerrar el navegador? Close All Tabs nos permite cerrar todas las pestañas que tengamos abiertas menos la pestaña que estemos [...]

]]> Comment on Sparrow 0.9: New Xcode Templates by Thomashttp://www.sodeso.nl/?p=1225&cpage=1#comment-1006 Thomas Fri, 20 Aug 2010 15:46:12 +0000 http://www.sodeso.nl/?p=1225#comment-1006 Hi Ronald, thank you for the templates! Only one problem: The clean iPad only template does not compile (the iPhone and Universal ones do, so I think I set everything up correctly =)Errors: http://imgur.com/i3MZP.png Hi Ronald, thank you for the templates!
Only one problem: The clean iPad only template does not compile (the iPhone and Universal ones do, so I think I set everything up correctly =)

Errors: http://imgur.com/i3MZP.png

]]> Comment on Installing and using Apache Cassandra With Java Part 1 (Installation) by Ronald Mathieshttp://www.sodeso.nl/?p=80&cpage=1#comment-1005 Ronald Mathies Wed, 18 Aug 2010 08:22:45 +0000 http://www.sodeso.nl/?p=80#comment-1005 Where clauses are not possible within the Cassandra database. What you normally do is create multiple inverted index ColumnFamilies. The advantage of this is that retrieving data based on keys is very fast and efficient. Since Cassandra only allows you to define a single key value you need to figure out what your search paths are. Suppose i have a table with cars. If i would like to search all cars from a single brand i would create a ColumnFamily where the key is the brand name and columns are the ID's of the cars. But if i want to search cars by engine type i would need to create another ColumnFamily where the engine type is the Key and the columns are the ID's of the cars. These two column families don't have any information about the cars itself except the key information.A third Column family would be needed to store the car details where the key is the ID of the car en de columns the details.About the business logic, Cassandra itself doesn't provide any means or methods for handling business methods. So you would need to apply business logic from within the client before storing data or after retrieving data. Also keep in mind that the consistency between the two tables needs to be handled, what happens if data is removed from one database but us dependent on the data in the other database?But some questions, the table you are referring to, how much data does it contain? What is the structure of the data? Where clauses are not possible within the Cassandra database. What you normally do is create multiple inverted index ColumnFamilies. The advantage of this is that retrieving data based on keys is very fast and efficient. Since Cassandra only allows you to define a single key value you need to figure out what your search paths are. Suppose i have a table with cars. If i would like to search all cars from a single brand i would create a ColumnFamily where the key is the brand name and columns are the ID’s of the cars. But if i want to search cars by engine type i would need to create another ColumnFamily where the engine type is the Key and the columns are the ID’s of the cars. These two column families don’t have any information about the cars itself except the key information.

A third Column family would be needed to store the car details where the key is the ID of the car en de columns the details.

About the business logic, Cassandra itself doesn’t provide any means or methods for handling business methods. So you would need to apply business logic from within the client before storing data or after retrieving data. Also keep in mind that the consistency between the two tables needs to be handled, what happens if data is removed from one database but us dependent on the data in the other database?

But some questions, the table you are referring to, how much data does it contain? What is the structure of the data?

]]> Comment on Installing and using Apache Cassandra With Java Part 1 (Installation) by mallikarjunhttp://www.sodeso.nl/?p=80&cpage=1#comment-1004 mallikarjun Wed, 18 Aug 2010 07:47:12 +0000 http://www.sodeso.nl/?p=80#comment-1004 Hi,I have a requirement of using Cassandra in my application. In my application there is one table with lot of data and most of my application uses that table. Due to lot of data,performance of the application is decreasing when i use that table is in Oracle.So, I have decided to use the Cassandra database for that one table and all other tables in oracle. Lot of business logic is dependent on that table.No my question is, Can I use the Cassandra for a table which has lot of business logic.I am unable to implement lot of where clauses for Cassandra database.Is there any supporting tool to use Cassandra in an efficient way?Please let me know... i am in urgency..Thanks in advanceBy Mallik Hi,

I have a requirement of using Cassandra in my application. In my application there is one table with lot of data and most of my application uses that table. Due to lot of data,performance of the application is decreasing when i use that table is in Oracle.

So, I have decided to use the Cassandra database for that one table and all other tables in oracle. Lot of business logic is dependent on that table.

No my question is, Can I use the Cassandra for a table which has lot of business logic.

I am unable to implement lot of where clauses for Cassandra database.

Is there any supporting tool to use Cassandra in an efficient way?

Please let me know…
i am in urgency..

Thanks in advance

By Mallik

]]> Comment on Installing and using Apache Cassandra With Java Part 4 (Thrift Client) by Ronald Mathieshttp://www.sodeso.nl/?p=251&cpage=1#comment-1002 Ronald Mathies Fri, 13 Aug 2010 07:59:29 +0000 http://www.sodeso.nl/?p=251#comment-1002 <a href="#comment-1001" rel="nofollow">@ Ronald Mathies </a>Sadly (well, actually for good reasons), no, you cannot switch them around since the "Authors" is the ColumnFamily name.The reason it works like this is because you can store several different structures for the same key in different ColumnFamilies. Allowing you to store mutual related data all at once. I can imagine that the naming of the method is a bit confusing since it is called batch_xxx, so yes, in the beginning i also thought that it would be possible to store several keys at the same time. @ Ronald Mathies

Sadly (well, actually for good reasons), no, you cannot switch them around since the “Authors” is the ColumnFamily name.

The reason it works like this is because you can store several different structures for the same key in different ColumnFamilies. Allowing you to store mutual related data all at once. I can imagine that the naming of the method is a bit confusing since it is called batch_xxx, so yes, in the beginning i also thought that it would be possible to store several keys at the same time.

]]>