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From Jonathan Ellis <>
Subject Re: Fixing the data model names
Date Thu, 13 Aug 2009 01:21:38 GMT
On Wed, Aug 12, 2009 at 7:52 PM, Michael Koziarski<> wrote:
> However I think it's worth considering this from a strategic
> perspective, looking at how we want the project do grow and change,
> rather than just as it is right now.  The key to successful adoption
> is having a successful elevator pitch,  you can start using a database
> without understanding relational-algebra because 'table' and 'column'
> are such simple ways to reason about the tool.  As it stands
> cassandra's takes a whiteboard and 15 minutes, before people get what
> you're talking about.

If you want to explain it as "sort of like a relational db" then

table -> CF
column -> column
key -> key
row -> row

That's the simple case, then all you have is "supercolumns can contain
a list of simple columns."

That really doesn't seem so hard to me.  I have explained this to *managers*.

> Assuming the project gets anything like the adoption it deserves, the
> users we have today will be a *tiny minority* of the users we have in
> the future.  So imposing costs on the current userbase which will give
> huge benefits to future users, should be something we're willing to
> do.  In fact it's something that has been done repeatedly over the
> last few weeks.

I agree.  But as I said before I just don't see this as being an improvement.

> Given those changes went in without debate, I'm not sure what the
> reluctance is for making changes to the nomenclature for the project.

As above.

> Speaking as someone who's only been doing this a month, the naming is
> *still* confusing, and when I talk with people who wonder what
> cassandra is all about I get blank looks when telling them what things
> are called.  If you step back and want to tell someone how you'd
> insert a tweet into someone's timeline using evan's weblog post:
>  "You just take the user's key, and use that to insert into the
> SuperColumnFamily 'UserAssociations' at SubColumn 'user_timeline', a
> ColumnName of a time based uuid representing now, and a value of the
> new tweet's key"
> Column is in the name of 3 of the 5 concepts expressed, and in each
> cases it's different.

When you're inserting something nested 3 levels deep a certain amount
of verbosity is unavoidable.  With Evan's nomenclature,

"You take the user's record ID, and use that to insert into the Record
Collection 'user associations' at Attribute Collection
'user_timeline,' an Attribute named with a time based uuid
representing now, and with a value of the new tweet's key."

I think that is a negative improvement.  Yay, now we are talking about
Attribute Collections and Attributes instead of SuperColumns and
Columns.  The same objections ("one object's name contains the
other's!) apply, plus the new one of sounding so generic that it could
apply to practically any system.


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