A list is simply a list of things. The list has no structure, except in some cases, the length of the list may be known. The list may contain duplicate items. In the following example the number 1 is included twice.

Example list:

1
2
3
1

A set is similar to a list, but has the following differences:

1. The size of the set is always known
   
2. A set may not contain duplicates
   

You can convert a list to a set by creating a 'weighted list'. The weighted list includes a count column so that you can determine when an item in the list appears more than once:

1,2
2,1
3,1

Notice that there are two number 1 values in the weighted list. In order to make insertions into such a list scalable, consider using partitioning to avoid large indexes.

…

A list is simply a list of things. The list has no structure, except in some cases, the length of the list may be known. The list may contain duplicate items. In the following example the number 1 is included twice.

Example list:

1
2
3
1

A set is similar to a list, but has the following differences:

1. The size of the set is always known
   
2. A set may not contain duplicates
   

You can convert a list to a set by creating a 'weighted list'. The weighted list includes a count column so that you can determine when an item in the list appears more than once:

1,2
2,1
3,1

Notice that there are two number 1 values in the weighted list. In order to make insertions into such a list scalable, consider using partitioning to avoid large indexes.

…

I have an interesting problem, on a data migration project I'm currently working on. I'm importing a large amount of legacy data into Drupal, using the awesome Migrate module (and friends). Migrate is a great tool for the job, but one of its limitations is that it requires the legacy database tables to have non-composite integer primary keys. Unfortunately, most of the tables I'm working with have primary keys that are either composite (i.e. the key is a combination of two or more columns), or non-integer (i.e. strings), or both.

Table with composite primary key.

The simplest solution to this problem would be to add an auto-incrementing integer primary key column to the legacy tables. This would provide the primary key information that Migrate needs in order to do its mapping of legacy IDs to Drupal IDs. But this solution has a serious drawback. In my project, …

I have an interesting problem, on a data migration project I'm currently working on. I'm importing a large amount of legacy data into Drupal, using the awesome Migrate module (and friends). Migrate is a great tool for the job, but one of its limitations is that it requires the legacy database tables to have non-composite integer primary keys. Unfortunately, most of the tables I'm working with have primary keys that are either composite (i.e. the key is a combination of two or more columns), or non-integer (i.e. strings), or both.

Table with composite primary key.

The simplest solution to this problem would be to add an auto-incrementing integer primary key column to the legacy tables. This would provide the primary key information that Migrate needs in order to do its mapping of legacy IDs to Drupal IDs. But this solution has a serious drawback. In my project, …

UPDATED - I had to update this post after a conversation with RightScale founder and CTO Thorsten von Eicken and for Sun’s Open Cloud announcement, which are both now included below.

There has been some substantial technology and news regarding open source software in cloud computing lately. More proof that open source is reaching into nearly all aspects of enterprise and broader IT, and also reinforcement of the idea that open source software will continue to have a pervasive and disruptive impact on the way organizations of all shapes and sizes do their computing and deal with their data.

First up is RightScale, which as detailed by 451 colleague and Principal Analyst William Fellows, is up and running across the pond on Amazon’s EU EC2. As WiF reports, RightScale started with …

Ok, Now we are talking!

Oh well, we know the Obama team is quite technology savvy and want to run the administration on the state of the art computer technologies. As an example, Obama campaign website used MySQL on the backend. 

So then, can Cloud Computing benefits lure the administration? Security and Technology experts discuss on national public radio  if Cloud Computing will work for the White House and how their computers should run.  Kevin L. Jackson further muses if the Obama Administration should use Cloud Computing.  He believes that Cloud Computing technology can indeed be used to implement the recommendations made by …

Ok, Now we are talking!

Oh well, we know the Obama team is quite technology savvy and want to run the administration on the state of the art computer technologies. As an example, Obama campaign website used MySQL on the backend. 

So then, can Cloud Computing benefits lure the administration? Security and Technology experts discuss on national public radio  if Cloud Computing will work for the White House and how their computers should run.  Kevin L. Jackson further muses if the Obama Administration should use Cloud Computing.  He believes that Cloud Computing technology can indeed be used to implement the recommendations made by …

Ok, Now we are talking!

Oh well, we know the Obama team is quite technology savvy and want to run the administration on the state of the art computer technologies. As an example, Obama campaign website used MySQL on the backend. 

So then, can Cloud Computing benefits lure the administration? Security and Technology experts discuss on national public radio  if Cloud Computing will work for the White House and how their computers should run.  Kevin L. Jackson further muses if the Obama Administration should use Cloud Computing.  He believes that Cloud Computing technology can indeed be used to implement the recommendations made by …

The Cloud Computing Expo at Fairmont Hotel in san Jose, CA is fast approaching and I plan to be there to learn and meet the folks interested in Cloud Computing. If you plan to be there, dont miss the hands on Cloud Computing BootCamp, also being held at Fairmont hotel on 20th Nov. and is Free.

Led by Williamson, the Cloud Computing Bootcamp will illustrate all the major players and provide a hands-on program with configuration samples, live demos and working setups you can further adapt and play with.

Hope to see you there and chat about how you can leverage the Sun Cloud offerings to build applications for the cloud or build your own clouds.

The Cloud Computing Expo at Fairmont Hotel in san Jose, CA is fast approaching and I plan to be there to learn and meet the folks interested in Cloud Computing. If you plan to be there, dont miss the hands on Cloud Computing BootCamp, also being held at Fairmont hotel on 20th Nov. and is Free.

Led by Williamson, the Cloud Computing Bootcamp will illustrate all the major players and provide a hands-on program with configuration samples, live demos and working setups you can further adapt and play with.

Hope to see you there and chat about how you can leverage the Sun Cloud offerings to build applications for the cloud or build your own clouds.