# EXPLAIN REBALANCE PARTITIONS

The `EXPLAIN REBALANCE PARTITIONS` command returns the set of steps that `REBALANCE PARTITIONS` would run.

## Syntax

```sql
EXPLAIN REBALANCE PARTITIONS ON db_name

```

## Remarks

* `db_name` - name of a SingleStore database.
* [Node Requirements for SingleStore Commands](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands.md)
* See [MV\_REBALANCE\_STATUS](https://docs.singlestore.com/db/v9.1/reference/information-schema-reference/segment-column-and-merge-status/mv-rebalance-status.md) for the column definitions in the result set.

The *Ordinal* is the target partition’s ordinal, and the *Target\_Host* and *Target\_Port* correspond to the destination leaf. Any two operations in the same *Phase* can be run in parallel and phases are run in order. For example, the aggregator can run `COPY PARTITION` on partitions `test:1` and `test:3` in parallel. The exact meaning of what each phase means is arbitrary and depends on the particular rebalance operation. The `Estimated_Time_Remaining_Ms` is the estimated total time (in milliseconds) that each low-level command will take to complete.

## Example

```sql
EXPLAIN REBALANCE PARTITIONS ON memsql_demo;

```

```output

+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
| Action                      | Ordinal | Target_Host | Target_Port | Phase | Estimated_Time_Remaining_Ms |
+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
| COPY PARTITION              | 13      | 127.0.0.1   | 10002       | 3     | 7821                        |
| COPY PARTITION              | 2       | 127.0.0.1   | 10003       | 4     | 7821                        |
| COPY PARTITION              | 2       | 127.0.0.1   | 10004       | 4     | 7821                        |
| PROMOTE PARTITION WITH DROP | 2       | 127.0.0.1   | 10003       | 5     | 1351                        |
| DROP PARTITION              | 2       | 127.0.0.1   | 10002       | 6     | 1002                        |
| DROP PARTITION              | 13      | 127.0.0.1   | 10004       | 6     | 1002                        |
+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
```

**Note**: The `Estimated_Time_Remaining_Ms` is the estimated total time (in milliseconds) that each low-level command will take to complete.

## Understanding the Rebalance Actions

Each action occurs on a single partition.

| Action                                    | Definition                                                                                                                                                                                                                                                                                                                 |
| ----------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `COPY PARTITION`                          | Copies a partition and sets upreplication (Ensures redundancy in a cluster. There are two types of replication: high availability - replicating partitions between the leaf nodes and cluster replication - replicating partitions between clusters.)to keep the copy in sync.                                             |
| `PROMOTE PARTITION [WITH {DROP,REPOINT}]` | Promotes a replica partition into a master partition. The`WITH DROP`clause drops the previous master partition. The`WITH REPOINT`clause converts the previous master partition into a replica partition. There is no default, rebalance chooses one or the other based on the path to get to a balanced set of partitions. |
| `DROP PARTITION`                          | Drops a partition.                                                                                                                                                                                                                                                                                                         |

***

Modified at: June 12, 2026

Source: [/db/v9.1/reference/sql-reference/cluster-management-commands/explain-rebalance-partitions/](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands/explain-rebalance-partitions/)

(An index of the documentation is available at /llms.txt)