在mongodb中创建索引的问题

Question

无法为大数据列创建索引低于错误

语法 db.APP_AIR.createIndex ({Message : 1})

Btree::insert: key too large to index, failing APP_LOG_11032016.APP_AIR.$Message_1 4058 { : "Back in 2006, we at SSSSfelt compelled to provide the hundreds of millions of underbanked SSSS, who do not have the ability to make payments onl..." }

请帮我解决这个问题。