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- sh.addTagRange()
sh.addTagRange()¶
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Definition¶
-
sh.
addTagRange
(namespace, minimum, maximum, tag)¶ Changed in version 3.4: This method aliases to
sh.updateZoneKeyRange()
in MongoDB 3.4. The functionality specified below still applies to MongoDB 3.2. MongoDB 3.4 provides Zone sharding as the successor to tag-aware sharding.Attaches a range of shard key values to a shard tag created using the
sh.addShardTag()
method.sh.addTagRange()
takes the following arguments:Parameter Type Description namespace
string The namespace of the sharded collection to tag. minimum
document The minimum value of the shard key range to include in the tag. The minimum is an inclusive match. Specify the minimum value in the form of <fieldname>:<value>
. This value must be of the same BSON type or types as the shard key.maximum
document The maximum value of the shard key range to include in the tag. The maximum is an exclusive match. Specify the maximum value in the form of <fieldname>:<value>
. This value must be of the same BSON type or types as the shard key.tag
string The name of the tag to attach the range specified by the minimum
andmaximum
arguments to.Use
sh.addShardTag()
to ensure that the balancer migrates documents that exist within the specified range to a specific shard or set of shards.Only issue
sh.addTagRange()
when connected to amongos
instance.
Behavior¶
Bounds¶
Zone ranges are always inclusive of the lower boundary and exclusive of the upper boundary.
Dropped Collections¶
If you add a tag range to a collection using
sh.addTagRange()
and then later drop the collection
or its database, MongoDB does not remove the tag association. If you
later create a new collection with the same name, the old tag
association will apply to the new collection.
Example¶
Given a shard key of {state: 1, zip: 1}
, the following operation
creates a tag range covering zip codes in New York State:
sh.addTagRange( "exampledb.collection",
{ state: "NY", zip: MinKey },
{ state: "NY", zip: MaxKey },
"NY"
)