order of values in multi-valued fields

[Dmitri Maziuk]

Hi all,

I can't find anything in TFM on this: does Solr make any promises about 
the order of values in a multi-valued field?

I.e. is it like python containers that keep insertion order until 
sorted, SQL resultsets that come in "any order" unless explicitly 
sorted, or C "undefined behaviour" that may kill your pets, burn your 
house down, and sing limericks over the ashes?

We have plenty of documents that contain ordered lists of images. I 
don't see a good way to maintain that order in the Solr document:

- we could make them child documents with "index number" field, but 
child documents tend to be a PITA to deal with,

- we could make a delimited "compound" field (e.g. "1:${image}" but that 
also requires extra work to render client-side,

- the easy way out is stick them into a multi-valued field but is there 
any guarantee that its values will be returned in the order of insertion?

TIA
Dima