lexorank
A simple implementation of LexoRank
LexoRank is a ranking system introduced by Atlassian JIRA.
Background
What is the best representation of an ordered list in a database? With a dumb order number based ranking system, re-ordering a row of a list may require updating all rows of the list in a transaction, which is O(n).
- https://stackoverflow.com/questions/9536262/best-representation-of-an-ordered-list-in-a-database/49956113
- https://softwareengineering.stackexchange.com/questions/195308/storing-a-re-orderable-list-in-a-database
LexoRank makes it O(1). All you need to do is updating the re-ordered row's order field.