What I essentially want, is to retreive all features and values of products which have a particular feature and value.

For example: I want to know all available hard drive sizes of products that have an Intel processor.

I have three tables:

product_to_value (product_id, feature_id, value_id)
features (id, value) // for example Processor family, Storage size, etc.
values (id, value) // for example Intel, 60GB, etc

The simplified query I have now:

SELECT
   features.name,
   featurevalues.name,
   featurevalues.value
FROM
   products,
   products as prod2,
   features,
   features as feat2,
   values,
   values as val2
WHERE
   products.feature = features.id
   AND
   products.value = values.id
   AND
   products.product = prod2.product
   AND
   prod2.feature_id = feat2.id
   AND
   prod2.value_id = val2.id
   AND
   features.id = ?
   AND
   feat2.id = ?

All columns have an index. I am using SQLite.

The problem is that it's very slow (70ms per query, without the self-join it's <1ms). Is there a smarter way to fetch data like this? Or is this too much to ask from SQLite?

I personally think I am simply overlooking something, as I am quite new to SQLite.