We have a GIS based database. All documents contain longitude and latitude. Currently we have our shard key set to longitude. We are considering changing it to a combination of longitude and latitude. We believe that, in doing so, we will not only greatly increase the cardinality of keys, but will also distribute our data more evenly across the shards. We also expect to see an improvement in the time it takes to load and query data. We'd like your opinion on this.
Thanks in advance for you help.