Indexing an associative array

I want to index an associative array which is as shown below

A=10238121
B=4700-12-31
C=123
D=ear

where A,B,C,D are keys with their respective values.

Now there are 2 approaches towards indexing it,

Approach 1
--------------
In a Lucene document, I create 2 fields with names "key" and "values" and I index A,B,C,D into "key" and their corresponding values into "values" field.

Approach 2
--------------
In a Lucene document, I create 4 fields with their names as A,B,C,D and their values as 10238121,...,ear.

Which approach of these two should be used. Will difference in approach affect the search results ?

Hi.
You didn't point about your model. Is that data one model or that is difference data.
I.e. if you use first approach you will make four difference Documents. But in second approach you will use only one Document.
Of course for search faster will be second approach. But I can't say exactly, because I don't know your architecture.

I didn't get you regarding the model I'm using.

Does it mean what I'm indexing and searching on ?

I'm sorry I don't understand you.
You asked about performance Lucene for two approaches in create index.
I answered that second approach faster then first.

ok...thanks :)