elasticsearch/elasticsearch — pull request #6504 by kimchy (2014-06-15 22:52:19+00:00)
Title: Better default size for global index -> alias map

The alias -> (index -> alias) map, specifically the index -> alias one, typically just hold one entry, yet we eagerly initialize it to the number of indices. When there are many indices, each with many aliases, this is a very large overhead per alias...