Release Notes for MariaDB Xpand 6.0.6

Overview

MariaDB Xpand is a distributed SQL database.

MariaDB Xpand 6.0.6 was released on 2022-12-08.

Notable Changes

  • Added the rebalancer_rebalance_mode global variable to control the Xpand Rebalancer swapping behavior. (XPT-326)

    • When rebalancer_rebalance_mode="normal" is set (the default), the rebalancer will swap slices between nodes to improve data distribution.

    • When rebalancer_rebalance_mode="noswap" is set, the rebalancer will move slices to even out distribution, but will not swap slices between nodes.

  • Added support for ALTER TABLE... RENAME COLUMN syntax to rename a column. (XPT-504)

    • This ALTER TABLE operation is instant. It only requires the table's metadata to change, which allows the operation to complete instantly without rebuilding the table.

    • The column being renamed cannot be modified by another ALTER specification within the same ALTER statement.

Issues Fixed

Can Result in Data Loss

  • The number of healthy replicas and healthy zones for binlog segments is computed incorrectly. This can break replication with the error: (XPT-457)

    Binlog's segment is inaccessible.
    

Can Result in Unexpected Behavior

  • When softfailing a majority of nodes, binlog reprotection does not complete during softfail.

Installation Instructions

Upgrade Instructions