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MongoDB: If a collection is not sharded, does the mongos perform a merge-sort before returning the result of a query?

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MongoDB: If a collection is not sharded, does the mongos perform a merge-sort before returning the result of a query?
posted Feb 17, 2016 by anonymous

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Yes It will perform merge sort but in primary shard.
commented Feb 26, 2016 by Shivam Kumar Pandey

1 Answer

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Here is the flow:
Step1:(All unsharded Collection in sharded database)All database in a sharded cluster have a “primary shard.” All unsharded collection within that database will reside on the same shard.
Step2.After a query,Merging result from other shards
Step3.Performs merge sort in primary shard in mongod
step4.Data returned to Mongos.

This image will clear your concept about shardening and Mongos #ReferenceOfImage -

answer Feb 26, 2016 by Shivam Kumar Pandey
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