DBLE 3.20.07.0 Release Notes and Feature Overview

DBLE is an enterprise‑grade open‑source distributed middleware (nicknamed “MyCat Plus”) that provides data horizontal partitioning, read/write separation, distributed transaction support, and a rich set of sharding algorithms.

The new 3.20.07.0 version, released on the day of the article, adds six refactored configuration functions, fixes sixteen defects, and makes one backward‑compatibility adjustment.

Key updates include:

1. Configuration file refactor

The dble_update_config tool upgrades configurations from version 2.20.04.0 to 3.20.07.0 (earlier versions should first upgrade to 2.20.04.0). It reads files such as myid.properties, wrapper.conf, server.xml, schema.xml, rule.xml, log4j2.xml, and optional property files, then writes the new cluster.cnf, bootstrap.cnf, user.xml, db.xml, sharding.xml, etc.

dble_update_config [-i=read_dir] [-o=write_dir] [-p=rootPath]

2. Expanded DML push‑down support for non‑sharded tables

The release enables direct push‑down of four DML statements (INSERT … SELECT, DELETE with multi‑table joins, UPDATE with multi‑table joins, and similar INSERT … SELECT for tables sharing the same sharding rule) to MySQL.

3. Online DDL support

Online DDL operations (index, primary key, column, generated column, foreign key, table, tablespace, and partitioning changes) can now be executed without table locks, reducing downtime in clustered environments.

Feature list (selected):

[#1879] Refactored connection‑pool code.

[#1863] More DML statements can be pushed down to MySQL.

[#1849] Major configuration file changes; upgrade tool provided.

[#1848] Online DDL support.

[#1846] Query sending via WriteToBackendExecutor for complex queries.

[#1906] Alpha support for OGG data‑synchronization tool.

Bug fixes (selected):

[#2030] Fixed hanging when executing complex SQL with many UNIONs.

[#2029] Resolved "field not found" error for Chinese column names.

[#2025] Handled constant expressions in SELECT statements.

[#1820] Fixed image saving issues with setBlob/setBinaryStream.

[#1788] Fixed front‑end connection timeout affecting heartbeat detection.

The full release notes and Chinese translation are available on the GitHub releases page, and the official documentation has been updated accordingly.

Additional resources include links to the DBLE project repository, documentation, download URLs, and related tutorial videos.