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ALTER RANGE

Currently, the ALTER RANGE statement can only be used to modify the range of a specific placement policy in TiDB.

Note

This feature is not available on TiDB Serverless clusters.

Synopsis

AlterRangeStmt

AlterRangeStmt ::=
    'ALTER' 'RANGE' Identifier PlacementPolicyOption

ALTER RANGE supports the following two parameters:

global: indicates the range of all data in a cluster.
meta: indicates the range of internal metadata stored in TiDB.

Examples

CREATE PLACEMENT POLICY `deploy111` CONSTRAINTS='{"+region=us-east-1":1, "+region=us-east-2": 1, "+region=us-west-1": 1}';
CREATE PLACEMENT POLICY `five_replicas` FOLLOWERS=4;

ALTER RANGE global PLACEMENT POLICY = "deploy111";
ALTER RANGE meta PLACEMENT POLICY = "five_replicas";

The preceding example creates two placement policies (deploy111 and five_replicas), specifies constraints for different regions, and then applies the deploy111 placement policy to all data in the cluster range and the five_replicas placement policy to the metadata range.