# Percona XtraDB Cluster 8.0.31-23 (2023-03-14)

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| Release date | {{ release_date }} |
|---|---|
| Install instructions | [Install Percona XtraDB Cluster](https://docs.percona.com/percona-xtradb-cluster/8.0/install-index.html) |

Percona XtraDB Cluster (PXC) supports critical business applications in your public, private, or hybrid cloud environment. Our free, open source, enterprise-grade solution includes the high availability and security features your business requires to meet your customer expectations and business goals.

## Release highlights

Percona XtraDB Cluster is based on Percona Server for MySQL. Find a complete list of improvements and bug fixes in the [Percona Server for MySQL 8.0.31-23 (2022-11-21) release notes](https://docs.percona.com/percona-server/8.0/release-notes/8.0.31-23.html).

This release adds the following feature in [tech preview](/glossary.md#tech-preview):

* [GCache encryption and Write-Set cache encryption](/gcache-write-set-cache-encryption.md)

Improvements and bug fixes introduced by Oracle for MySQL 8.0.31 and included in Percona Server for MySQL are the following:

* MySQL adds support for the SQL standard [`INTERSECT`](https://dev.mysql.com/doc/refman/8.0/en/intersect.html) and [`EXCEPT`](https://dev.mysql.com/doc/refman/8.0/en/except.html) table operators.

* InnoDB supports parallel index builds. This improves index build performance. The sorted index entries are loaded into a B-tree in a multithread. In previous releases, this action was performed by a single thread.

* The Performance and sys schemas show metrics for the global and session memory limits introduced in MySQL 8.0.28.

    The following columns have been added to the Performance Schema tables:

    | Performance Schema tables                                                            | Columns                                                   |
    | ------------------------------------------------------------------------------------ | --------------------------------------------------------- |
    | SETUP_INSTRUMENTS                                                                    | FLAGS                                                     |
    | THREADS                                                                              | CONTROLLED_MEMORY, MAX_CONTROLLED_MEMORY, TOTAL_MEMORY, MAX_TOTAL_MEMORY |
    | EVENTS_STATEMENTS_CURRENT, EVENTS_STATEMENTS_HISTORY, EVENTS_STATEMENTS_HISTORY_LONG | MAX_CONTROLLED_MEMORY, MAX_TOTAL_MEMORY                   |
    | Statement Summary Tables                                                             | MAX_CONTROLLED_MEMORY, MAX_TOTAL_MEMORY                   |
    | Performance Schema Connection Tables                                                 | MAX_SESSION_CONTROLLED_MEMORY, MAX_SESSION_TOTAL_MEMORY   |
    | PREPARED_STATEMENTS_INSTANCES                                                        | MAX_CONTROLLED_MEMORY, MAX_TOTAL_MEMORY                   |

    The following columns have been added to the sys schema `STATEMENT_ANALYSIS` and `X$STATEMENT_ANALYSIS` views:

    * MAX_CONTROLLED_MEMORY

    * MAX_TOTAL_MEMORY

    The `controlled_by_default` flag has been added to the `PROPERTIES` column of the `SETUP_INSTRUMENTS` table.

    Now, you can add and remove non-global memory instruments to the set of controlled-memory instruments. To do this, set the value of the `FLAGS` column of `SETUP_INSTRUMENTS`.

    ```sql
    SQL> UPDATE PERFORMANCE_SCHEMA.SETUP_INTRUMENTS SET FLAGS="controlled" 
    WHERE NAME='memory/sql/NET::buff';
    ```

* The `audit_log_flush` variable has been deprecated and will be removed in future releases.

Find the full list of bug fixes and changes in the [MySQL 8.0.31 Release Notes](https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-31.html).

## New Features

* Added support for [GCache and Write-Set encryption](/gcache-write-set-cache-encryption.md).

* [PXC-3574](https://jira.percona.com/browse/PXC-3574): Added support for the `wsrep_mode` variable.

## Improvement

* The Data at Rest encryption now encrypts Record-Set cache.

## Bug fixes

* [PXC-3989](https://jira.percona.com/browse/PXC-3989): Added support for keyring components. 

* [PXC-4077](https://jira.percona.com/browse/PXC-4077): Injecting an empty transaction caused GTID inconsistencies between nodes.

* [PXC-4120](https://jira.percona.com/browse/PXC-4120): Enabling wsrep-debug created multiple entries of `wsrep_commit_empty()` in the Error log.

* [PXC-4126](https://jira.percona.com/browse/PXC-4126): When stream replication and TOI are active, the `CREATE USER` statement was not allowed.

* [PXC-4116](https://jira.percona.com/browse/PXC-4116): A PXC replica node stalled with parallel asynchronous parallel replication.

* [PXC-4148](https://jira.percona.com/browse/PXC-4148): A fix for the `MDL conflict db= ticket=10 solved by abort` error.

## Useful links

The [Percona XtraDB Cluster GitHub location](https://github.com/percona/percona-xtradb-cluster)

[Contribute to the documentation](https://github.com/percona/pxc-docs/blob/8.0/contributing.md)

For [training](https://www.percona.com/training), contact [Percona Training - Start learning now](https://learn.percona.com/contact-me).