该config_values表在 NDB 7.5.0 中实现，提供有关节点配置参数值当前状态的信息。表中的每一行对应于给定节点上参数的当前值。
node_id集群中节点的ID
config_param参数的内部 ID 号
config_value参数的当前值
笔记
此表的config_param列和
config_params表的
param_number列使用相同的参数标识符。通过在这些列上连接两个表，您可以获得有关所需节点配置参数的详细信息。此处显示的查询提供集群中每个数据节点上所有参数的当前值，按节点 ID 和参数名称排序：
Press CTRL+C to copySELECT v.node_id AS 'Node Id', p.param_name AS 'Parameter', v.config_value AS 'Value' FROM config_values v JOIN config_params p ON v.config_param=p.param_number WHERE p.param_name NOT LIKE '\_\_%' ORDER BY v.node_id, p.param_name;
在用于简单测试的小型示例集群上运行时，先前查询的部分输出：
Press CTRL+C to copy+---------+------------------------------------------+----------------+ | Node Id | Parameter | Value | +---------+------------------------------------------+----------------+ | 2 | Arbitration | 1 | | 2 | ArbitrationTimeout | 7500 | | 2 | BackupDataBufferSize | 16777216 | | 2 | BackupDataDir | /home/jon/data | | 2 | BackupDiskWriteSpeedPct | 50 | | 2 | BackupLogBufferSize | 16777216 | ... | 3 | TotalSendBufferMemory | 0 | | 3 | TransactionBufferMemory | 1048576 | | 3 | TransactionDeadlockDetectionTimeout | 1200 | | 3 | TransactionInactiveTimeout | 4294967039 | | 3 | TwoPassInitialNodeRestartCopy | 0 | | 3 | UndoDataBuffer | 16777216 | | 3 | UndoIndexBuffer | 2097152 | +---------+------------------------------------------+----------------+ 248 rows in set (0.02 sec)
该WHERE子句过滤掉名称以双下划线 ( ) 开头的参数__；这些参数保留供 NDB 开发人员测试和其他内部使用，不打算在生产 NDB Cluster 中使用。
通过发出适当的查询，您可以获得更具体、更详细或两者兼而有之的输出。
此示例提供有关当前为集群中所有数据节点设置
的NodeId、
NoOfReplicas、
HostName、
DataMemory、
IndexMemory和
参数的所有类型的可用信息
：TotalSendBufferMemory
Press CTRL+C to copySELECT p.param_name AS Name, v.node_id AS Node, p.param_type AS Type, p.param_default AS 'Default', p.param_min AS Minimum, p.param_max AS Maximum, CASE p.param_mandatory WHEN 1 THEN 'Y' ELSE 'N' END AS 'Required', v.config_value AS Current FROM config_params p JOIN config_values v ON p.param_number = v.config_param WHERE p. param_name IN ('NodeId', 'NoOfReplicas', 'HostName', 'DataMemory', 'IndexMemory', 'TotalSendBufferMemory')\G
在具有用于简单测试的 2 个数据节点的小型 NDB Cluster 上运行时，此查询的输出如下所示：
Press CTRL+C to copy*************************** 1. row *************************** Name: NodeId Node: 2 Type: unsigned Default: Minimum: 1 Maximum: 48 Required: Y Current: 2 *************************** 2. row *************************** Name: HostName Node: 2 Type: string Default: localhost Minimum: Maximum: Required: N Current: 127.0.0.1 *************************** 3. row *************************** Name: TotalSendBufferMemory Node: 2 Type: unsigned Default: 0 Minimum: 262144 Maximum: 4294967039 Required: N Current: 0 *************************** 4. row *************************** Name: NoOfReplicas Node: 2 Type: unsigned Default: 2 Minimum: 1 Maximum: 4 Required: N Current: 2 *************************** 5. row *************************** Name: DataMemory Node: 2 Type: unsigned Default: 102760448 Minimum: 1048576 Maximum: 1099511627776 Required: N Current: 524288000 *************************** 6. row *************************** Name: NodeId Node: 3 Type: unsigned Default: Minimum: 1 Maximum: 48 Required: Y Current: 3 *************************** 7. row *************************** Name: HostName Node: 3 Type: string Default: localhost Minimum: Maximum: Required: N Current: 127.0.0.1 *************************** 8. row *************************** Name: TotalSendBufferMemory Node: 3 Type: unsigned Default: 0 Minimum: 262144 Maximum: 4294967039 Required: N Current: 0 *************************** 9. row *************************** Name: NoOfReplicas Node: 3 Type: unsigned Default: 2 Minimum: 1 Maximum: 4 Required: N Current: 2 *************************** 10. row *************************** Name: DataMemory Node: 3 Type: unsigned Default: 102760448 Minimum: 1048576 Maximum: 1099511627776 Required: N Current: 524288000 10 rows in set (0.01 sec)