Querying this table provides information similar to that provided by the ALL REPORT MemoryUsage command in the ndb_mgm client, or logged by ALL DUMP 1000.

The following table provides information about the columns in the memoryusage table. For each column, the table shows the name, data type, and a brief description. Additional information can be found in the notes following the table.

The total column represents the total amount of memory in bytes available for the given resource (data memory or index memory) on a particular data node. This number should be approximately equal to the setting of the corresponding configuration parameter in the config.ini file.

Suppose that the cluster has 2 data nodes having node IDs 1 and 2, and the config.ini file contains the following:

[ndbd default]
DataMemory = 100M
IndexMemory = 100M

The following query shows approximately the same values:

mysql> SELECT node_id, memory_type, total 
     > FROM ndbinfo.memoryusage;
+---------+--------------+-----------+
| node_id | memory_type  | total     |
+---------+--------------+-----------+
|       1 | Data memory  | 104857600 |
|       1 | Index memory | 105119744 |
|       2 | Data memory  | 104857600 |
|       2 | Index memory | 105119744 |
+---------+--------------+-----------+
4 rows in set (0.30 sec)

In this case, the total column values for index memory are slightly higher than the value set of IndexMemory due to internal rounding.

For the used_pages and total_pages columns, resources are measured in pages, which are 32K in size for DataMemory and 8K for IndexMemory.