How to move an element in a sorted list and keep the CouchDb write "atomic"
- by karlthorwald
I have elements of a list in couchdb documents. Let's say these are 3 elements in 3 documents:
{ "id" : "783587346", "type" : "aList", "content" : "joey", "sort" : 100.0 }
{ "id" : "358734ff6", "type" : "aList", "content" : "jill", "sort" : 110.0 }
{ "id" : "abf587346", "type" : "aList", "content" : "jack", "sort" : 120.0 }
A view retrieves all "aList" documents and displays them sorted by "sort".
Now I want to move the elements, when I want to move "jack" to the middle, I could do this atomic in one write and change it's sort key to 105.0. The view now returns the documents in the new sort order.
After a lot of sorting I could end up with sort keys like 50.99999 and 50.99998 after some years and in extreme situations run out of digits?
What can you recommend, is there a better way to do this? I'd rather keep the elements in seperate documents. Different users might edit different elements in parallel (which also can get tricky).
Maybe there is a much better way?
