# 7. Checking Partition Number and Data Skew

This step checks whether there are enough partitions and if data is properly balanced across your cluster.

1. Check the total core-to-partition ratio per leaf for the database that is having trouble:

   * Run [SHOW PARTITIONS](https://docs.singlestore.com/db/v9.1/reference/sql-reference/show-commands/show-partitions.md) on the database in question and compare that with the total number of cores in your cluster.
   * Is this ratio at least 1:1? If you have high concurrency, consider increasing the concurrency from 2, 3, or 4 to 1 core to partition ratio.

2. Check that your data is balanced across the cluster properly by running [EXPLAIN REBALANCE PARTITIONS](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands/explain-rebalance-partitions.md) on the database in question. If you see a non-empty set, run [REBALANCE PARTITIONS](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands/rebalance-partitions.md) on the database.

3. Check that your data is redundant by running [EXPLAIN RESTORE REDUNDANCY](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands/explain-restore-redundancy.md). If you see a non-empty set, run [RESTORE REDUNDANCY](https://docs.singlestore.com/db/v9.1/reference/sql-reference/cluster-management-commands/restore-redundancy.md).

4. Data Skew: refer to the [Detecting and Resolving Data Skew](https://docs.singlestore.com/db/v9.1/create-a-database/detecting-and-resolving-data-skew.md).

## Next Steps

* If there are enough partitions and no data skew is detected: continue to [Step 8](https://docs.singlestore.com/db/v9.1/user-and-cluster-administration/troubleshooting/8-checking-for-system-changes-and-log-hints.md).

***

Modified at: July 17, 2024

Source: [/db/v9.1/user-and-cluster-administration/troubleshooting/7-checking-partition-number-and-data-skew/](https://docs.singlestore.com/db/v9.1/user-and-cluster-administration/troubleshooting/7-checking-partition-number-and-data-skew/)

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