Limit results on OR condition in Sphinx - sphinx

Question

I am trying to limit results by somehow grouping them,
This query attempt should makes things clear:
#namee ("Cameras") limit 5| #namee ("Mobiles") limit 5| #namee ("Washing Machine") limit 5| #namee ("Graphic Cards") limit 5
where namee is the column
Basically I am trying to limit results/ based upon specific criteria.
Is this possible ? Any alternative way of doing what I want to do.
I am on sphinx 2.2.9

Answer 1

There is no Sphinx syntax to do this directly.
The easiest would be just to do directly 4 separate queries and 'UNION' them in the application itself. Performance isn't going to be terrible.
... If you REALLY want to do it in Sphinx, can explicit a couple of tricks to get close, but it gets very complicated.
Would need to create 4 separate indexes (or upto as many terms as you need!). Each with the the same data, but with the field called something different. (they duplicate each other!) You would also need an attribute on each one (more on why later)
source str1 {
sql_query = SELECT id, namee AS field1, 1 as idx FROM ...
sql_attr_unit = idx
source str2 {
sql_query = SELECT id, namee AS field2, 2 as idx FROM ...
sql_attr_unit = idx
... etc
Then create a single distributed index over the 4 indexes.
Then can run a single query to get all results kinda magically unioned...
MATCH('##relaxed #field1 ("Cameras") | #field2 ("Mobiles") | #field3 ("Washing Machine") | #field4 ("Graphic Cards")')
(The ##relaxed is important, as the fields are different. the matches must come from different indexes)
Now to limiting them... Because each keyword match must come from a different index, and each index has a unique attribute, the attribute identifies what term matches....
in Sphinx, there is a nice GROUP N BY where you only get a certain number of results from each attribute, so could do... (putting all that together)
SELECT *,WEIGHT() AS weight
FROM dist_index
WHERE MATCH('##relaxed #field1 ("Cameras") | #field2 ("Mobiles") | #field3 ("Washing Machine") | #field4 ("Graphic Cards")')
GROUP 4 BY idx
ORDER BY weight DESC;
simples eh?
(note it only works if want 4 from each index, if want different limits is much more complicated!)