rails/arel — pull request #167 by pparidans (2013-03-03 15:32:57+00:00)
Title: Informix versions < 10 use 'FIRST' keyword instead of 'LIMIT'

Informix Versions <= 9 use the 'FIRST' keyword to limit the number of records returned.
Version 10 introduced the 'LIMIT' keyword as an alias.
As far as I know, upper versions still support 'FIRST' (at least until v11).