AJAX newb

[shown]

I have multiple visualizations whose data are subsets of one another.  It would seem multiple .php data connection files would be inefficient. 

[asgallant]

The Visualization API has a tool called a DataView, which can be used to filter a data set into subsets.  It allows you to select individual columns from the whole (or add new columns calculated based on the contents of other columns) or to filter rows by cell values (or both).