Oracle has announced the general availability of MySQL 9.7.0, marking the start of a new 9.7 LTS release series and the first major one since MySQL 8.4. The release arrives amid community concerns about declining MySQL development activity and Oracle's long-term commitment to the project.
The new release consolidates innovations from the recent development cycle, including improvements in replication observability, telemetry, and query optimization. Specifically, it improves the MySQL REST Service, adds the Hypergraph optimizer, and introduces new security features, including dynamic data masking and OpenID authentication. It also adds developer-focused enhancements such as in-database JavaScript and JSON duality, along with bug fixes and security patches. Mike Frank, product management director at Oracle, writes:
This release matters not only because it establishes the next LTS baseline, but because it reflects a broader direction for MySQL. Over the last several releases, we have talked about giving users earlier visibility into what is coming, broadening access to important capabilities, and working more openly with the MySQL community.
As previously covered on InfoQ, a MySQL repository analysis revealed declining development activity and a shrinking contributor base, and recent Oracle layoffs have further heightened community concerns.
With the 9.7 release, several capabilities previously available only in the Enterprise Edition are now available in the Community Edition. Frank adds:
The long-term goal is straightforward: to create a tighter feedback loop with the community and help craft the roadmap together.
The new LTS release comes at a time when many in the community are questioning Oracle's commitment to MySQL and its Community Edition. Oracle is working to reassure users following meetings about MySQL’s future, while new tracking forks are already underway to extend its capabilities.
MySQL 9.7.0 adds operational capabilities for DBAs and operators, including flow-control monitoring for visibility into cluster throttling, extended replication applier statistics to observe lag and throughput in multi-threaded replication, automatic eviction and rejoin of unhealthy cluster members, and primary election that favors the most up-to-date eligible node during failover.
The release also adds DML support for JSON Duality Views in MySQL Community Server, auto-increment support for JSON Duality View operations, and Hypergraph Optimizer support for improved optimization of complex queries. In a separate article, Øystein Grøvlen, senior principal software engineer at Oracle, writes:
The classic MySQL join optimizer is based on a long-standing left-deep search framework. That framework has been improved many times, but its basic shape makes some things hard (...) The hypergraph optimizer is useful because it makes several important choices first-class parts of optimization instead of afterthoughts.
Source: MySQL blog
Among the advantages of the Hypergraph optimizer are that interesting orders are now part of the search, nested-loop join versus hash join is a real cost-based choice, and bushy join plans are supported. Peter Zaitsev, founder of Percona and open source advocate, warns:
Hypergraph optimized in MySQL 9.7 makes many queries to run faster, but as it usually goes with optimizers not all of them - make sure to test how it impacts your application do not just assume it is newer... so it must be better.
For the Enterprise Edition, the release introduces Dynamic Data Masking, which protects sensitive data at query time by applying masking policies to table columns without requiring application changes.
With the general availability, a bug in the mysql-community.repo update (MySQL Bug #120315) silently disabled the 8.4 LTS repository and enabled 9.7 LTS instead, causing routine package updates to switch the major version a server follows.
MySQL 8.4 is currently set to reach end of life in three years.