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sh.splitAt(namespace, query)¶Splits a chunk at the shard key value specified by the query.
The method takes the following arguments:
namespace |
string | The namespace (i.e. <database>.<collection>) of the sharded collection that contains the chunk to split. |
query |
document | A query document that specifies the shard key value at which to split the chunk. |
The sh.splitAt() method wraps the split command.
In most circumstances, you should leave chunk splitting to the automated processes within MongoDB. However, when initially deploying a sharded cluster, it may be beneficial to pre-split manually an empty collection using methods such as sh.splitAt().
sh.splitAt() splits the original chunk into two chunks. One chunk has a shard key range that starts with the original lower bound (inclusive) and ends at the specified shard key value (exclusive). The other chunk has a shard key range that starts with the specified shard key value (inclusive) as the lower bound and ends at the original upper bound (exclusive).
To split a chunk at its median point instead, see sh.splitFind().
For the sharded collection test.foo, the following example splits a chunk at the shard key value x: 70.