Version information

About this version

1. OBKV supports aggregate functions such as MIN, MAX, and COUNT, auto-increment columns, and row data verification during data insertion.
2. The _ha_get_tablet_info_batch_count and _ha_rpc_timeout hidden parameters are added to control the number of tablets obtained by an RPC call at a time and the RPC timeout during operations such as migration, replication, rebuild, and physical restore. If the I/O operations on the SATA disk are slow, you can use the two parameters.
3. The DBMS_RESOURCE_MANAGER system package is provided in the community edition.
4. Issues encountered by customers and during internal tests are resolved to improve the stability of the product.

Fixed issues

• Fixed an issue that after the LIMIT pushdown statement is rewritten, the execution result of a LIMIT clause containing the RAND function is incorrect.
• Fixed an issue that if an expression contains functions such as USERENV and SYSDATE, the query result is inaccurate due to an incorrect query range.
• Fixed an issue that in the Prepared Statement (PS) protocol, a zero datetime value of the DATETIME type is not fully compatible with MySQL when an OBServer node sends a packet to the client. As a result, the query result on the client of the Go driver is abnormal.
• Fixed an issue that when the GROUP BY clause is used in a join of two tables, the returned result set does not meet the expectations.
• Fixed an issue that in a scenario where the cgroup feature is enabled and sql_nio is disabled, a core dump may occur due to the use of the PS protocol.
• Fixed an issue that if the CPU resources remain exhausted for a period of time, an OBKV request may time out and thereby cause a core dump.
• Fixed an issue that after the character set of a tenant is changed by using the ALTER DATABASE statement, the character set displayed in the information_schema.SCHEMATA view is incorrect.
• Fixed an issue that when a large number of DDL operations are performed on a single table, the minor compaction threads may be stuck due to too many involved partitions or intensive writes, which results in an out of memory (OOM) error.
• Fixed an issue that after the DOUBLE type is converted into the INT type in a query statement, the query result is inaccurate due to an incorrect query range.
• Fixed an issue that when an INSERT operation is performed in a scenario with a large data volume, a minor or major compaction will trigger a retry of the INSERT operation, which may result in discontinuous auto-increment IDs.
• Fixed an issue that during bypass import, the memory is used up because data of the ObArray type occupies memory of the sys500 tenant.
• Fixed an issue that when too many sessions exist in the sys tenant, the client may return the error session already exists.
• Fixed an issue that SqlExecutor memory bloats when a tenant with minimum specifications obtains the schemas.
• Optimized the performance in CPU over-allocation scenarios after the cgroup feature is enabled.

Considerations

OceanBase Database Community Edition can be directly upgraded from V4.1.0_CE_BP3 to V4.2.0 GA but not to V4.2.0_CE_Beta.

版本信息

发版目的

1. OBKV 支持 min、max、count 等汇聚函数，同时支持自增列和插入数据时的行数据校验。
2. 新增了两个隐藏配置项 _ha_get_tablet_info_batch_count 和 _ha_rpc_timeout，用于控制迁移复制、Rebuild 和物理恢复等操作中一次 RPC 批量获取 Tablet 的数量和 RPC 超时时间。这些配置项适用于 SATA 盘 IO 较慢的场景。
3. 开放 DBMS_RESOURCE_MANAGER 系统包到开源版本。
4. 解决客户及内部测试遇到的问题，提升版本稳定性。

缺陷修复

• 修复 limit push down 改写导致的带有 Rand 函数的 Limit 语句结果错误问题。
• 修复表达式中包含 USERENV、SYSDATE 等函数时，Query Range 错误导致查询结果不准确的问题。
• 修复在 PS 协议下，DATETIME 类型的 zero datetime 值在 OBServer 节点给客户端发包时没有完全与 MySQL 兼容，导致 Go 驱动客户端查询结果异常的问题。
• 修复两表 JOIN 使用 GROUP BY 语句时，返回结果集不符合预期的问题。
• 修复在开启 cgroup、关闭 sql_nio 场景下，使用 PS 可能触发的 Core 问题。
• 修复了 CPU 持续打爆的情况下，进行 OBKV 请求操作可能会导致超时并触发的 Core 问题。
• 修复 ALTER DATABASE 修改租户字符集后，information_schema.SCHEMATA 中字符集展示不正确问题。
• 修复在进行单表大量 DDL 操作时，同时分区数目较多或写入较多可能会触发转储线程卡住导致内存爆满的问题。
• 修复在查询语句中将 DOUBLE 类型转换为 INT 类型后，由于 Query Range 错误导致查询结果不正确的问题。
• 修复在大数量场景下进行 INSERT 操作时，触发某些转储/合并动作导致 INSERT 重试，可能导致自增 ID 跳变的问题。
• 修复在旁路导入时，由于 ObArray 类型使用了 500 租户的内存，导致内存爆满的问题。
• 修复 sys 租户积压场景下可能导致的客户端报错 session already exists 问题。
• 优化小规格租户在获取 Schema 过程中，SqlExecutor 内存膨胀问题。
• 优化开启 Cgroup 后，在 CPU 超卖场景下的性能表现。

注意事项

V4.1.0_CE_BP3 版本不支持升级到 V4.2.0_CE_Beta 版本，但支持升级到 V4.2.0 GA 版本。