Re: Tie breakers when sorting equal items

2014-01-27 Thread Erick Erickson
It's even worse. It may change. The internal tiebreaker is the
internal Lucene doc ID,
which may change one against another as segments are merged. So docA may
sort  docB for a while, then eventually sort docA  docB

I _think_ you can play games with the merge policy to anticipate this,
but really it'd be
much cheaper to add some kind of counter that you're guaranteed wouldn't change.

Best,
Erick

On Sun, Jan 26, 2014 at 12:01 PM, Scott Smith ssm...@mainstreamdata.com wrote:
 I promised to ask this on the forum just to confirm what I assume is true.

 Suppose you're returning results using a sort order based on some field (so, 
 not relevancy). For example, suppose it's a date field which indicates when 
 the document was loaded into the solr index.   Suppose two items have exactly 
 the same date/time in the field.  Would solr return the two items in the 
 order in which they were inserted.  I would assume that the answer is not 
 necessarily.

 I know that you can have secondary sort fields if something exists that would 
 provide the desired functionality.  I know that I could set up some kind of 
 numbering scheme that would provide the same result (the customer doesn't 
 want to pay for that).

 So, I'm really just asking if Solr has any guarantees that when you sort on a 
 field and two items have the same value, they will be sorted in the order 
 they were inserted into the index.  Again, I assume the answer is no, but I 
 said I would ask.


Tie breakers when sorting equal items

2014-01-26 Thread Scott Smith
I promised to ask this on the forum just to confirm what I assume is true.

Suppose you're returning results using a sort order based on some field (so, 
not relevancy). For example, suppose it's a date field which indicates when the 
document was loaded into the solr index.   Suppose two items have exactly the 
same date/time in the field.  Would solr return the two items in the order in 
which they were inserted.  I would assume that the answer is not necessarily.

I know that you can have secondary sort fields if something exists that would 
provide the desired functionality.  I know that I could set up some kind of 
numbering scheme that would provide the same result (the customer doesn't want 
to pay for that).

So, I'm really just asking if Solr has any guarantees that when you sort on a 
field and two items have the same value, they will be sorted in the order they 
were inserted into the index.  Again, I assume the answer is no, but I said I 
would ask.