Performance

I just have noticed

This way of writing the code is much faster

count(*[starts-with(name(),'DGBUIMSNNumber')][@action='add'])

than this way:

count(*[starts-with(name(),'DGBUIMSNNumber') and @action='add'])


Why is that?


And how do I write this piece of code like the above in the 'faster'
way?

count(*[starts-with(name(),'DGBUIMSNNumber') and (@action='default' or
@action='add')])


Because this would imply I had two 'and' instead of one 'and' and one
'or' correct?

count(*[starts-with(name(),'DGBUIMSNNumber')][@action='default'][@action
='add'])


Regards
Houman