Columns limit

[Mark]

Is there any limitations on the number of columns a row can have? Does 
all the day for a single key need to reside on a single host? If so, 
wouldn't that mean there is an implicit limit on the number of columns 
one can have... ie the disk size of that machine.

What is the proper way to handle timelines in this matter. For example 
lets say I wanted to store all user searches in a super column.

<ColumnFamily Name="SearchLogs"
                    ColumnType="Super"
                    CompareWith="TimeUUIDType"
                    CompareSubcolumnsWith="BytesType"/>

Which results in a structure as follows
{
   SearchLogs : {
       "foo" : {
            timeuuid_1 : { metadata goes here}
            timeuuid_2: { metadata goes here}
       },
       "bar" : {
            timeuuid_1 : { metadata goes here}
            timeuuid_2: { metadata goes here}
       }
  }
}

Couldn't this theoretically run out of columns for the same search term 
because for each unique term there can (and will) be many timeuuid columns?

Thanks for clearing this up for me.