See slide 44 here: http://thebuild.com/presentations/pg-as-nosql-pgday-fosdem-2013.pdf http://thebuild.com/presentations/pg-as-nosql-pgday-fosdem-2... GIN inde

See slide 44 here: http://thebuild.com/presentations/pg-as-nosql-pgday-fosdem-2013.pdf http://thebuild.com/presentations/pg-as-nosql-pgday-fosdem-2... GIN indexes are big, but Mongo's indexes are bigger than all other PostgreSQL indexes, and Mongo also requires much more space for the data.