Oracle has formed a new branch of the MySQL database management system, MySQL 9.1.0. Builds of MySQL Community Server 9.1.0 are prepared for all major distributions of Linux, FreeBSD, macOS, and Windows. Under the new release model implemented last year, MySQL 9.1 has been categorized under the 'Innovation' branches, which will also include the next significant release, MySQL 9.2. Innovation branches are recommended for those who want early access to new features, are published every three months, and are supported only until the next significant release is published (for example, support for branch 9.0 ceased after branch 9.1 was released). An LTS release is planned for the summer of next year, recommended for deployments that require predictability and a long-lasting unchanged behavior. Following the LTS branch, a new Innovation branch, MySQL 10.0, will be formed.
Key changes in MySQL 9.1:
- The 'CREATE VIEW' operation now includes support for the 'IF NOT EXISTS' expression, allowing the creation of a view only if a view with the specified name does not already exist, thereby avoiding an error if the view has already been created.
- Loading triggers during read-only operations has been eliminated. Previously, triggers were loaded on any access to a table, which led to memory consumption and CPU load in situations where triggers were not used (for example, during SELECT queries). In MySQL 9.1, the processing and loading of triggers are separated into two stages: reading metadata about the trigger and parsing + executing the trigger. Data obtained in the first stage is stored once and then shared across different instances of the trigger. Parsing and executing the trigger occurs only for expressions that result in data changes. Additionally, to reduce memory consumption, dynamic memory allocation for error handling in triggers has replaced static buffer allocation.
- The output of the 'EXPLAIN' operation has been expanded to now include information about the use of multi-range reading and the application of the semijoin strategy, where only rows from one table are processed during JOIN operations.
- Atomic execution of "CREATE DATABASE" and "DROP DATABASE" operations is ensured to protect against failures in the event of an unexpected termination or file system errors during these operations. For instance, earlier, an unexpected termination of "CREATE DATABASE" could result in the creation of an incomplete, non-working database storage structure, which required manual intervention for cleanup.
- Stored procedures written in JavaScript now support the VECTOR type. Data of this type can now be passed as input and return parameters.
- Added the ability to authenticate when connecting to the DBMS using the OpenID Connect protocol.
- 27 vulnerabilities have been fixed, with the most serious one (CVE-2024-5535) assigned a critical severity level (9.1 out of 10). The vulnerability can be exploited remotely without authentication. The issue is caused by reading data from outside the allocated buffer in the OpenSSL library, leading to a crash or memory content leakage in response after connecting to proxy server with incorrect protocol parameters.
Source: opennet.ru
