| Parameter | Description | Recommended value/range |
|---|---|---|
| memory_chunk_cache_size | The total cache size of the memory allocator. | The default value is 0. We recommend that you use the default value. |
| memory_limit_percentage | The maximum percentage of total memory that OceanBase Database can use. | We recommend that you set this parameter to a large value. |
| memstore_limit_percentage | The maximum percentage of MemStore memory in the tenant memory, which is non-exclusive. | Set this parameter to a sufficiently large value. An excessively large MemStore memory may cause the data writing speed to overrun the minor compaction speed and increase the risk of memory overflow. |
| freeze_trigger_percentage | The threshold for triggering a minor compaction. | For systems with heavy write load, we recommend that you set the value in the range of 30 to 50. This setting can trigger a minor compaction as soon as possible to avoid out-of-memory errors. However, minor compactions bring about additional CPU and I/O overhead. Frequent minor compactions generate an increasing number of mini SSTables, which increases the query path and degrades the query performance. In OceanBase Database V4.0 and later versions, this parameter is changed to a tenant-level parameter. |
| system_memory | The memory size reserved for the SYS500 tenant. | We recommend that you use the default value. |
| use_large_pages | Specifies whether to enable large memory pages. | The large memory pages feature takes effect only when it is enabled on the OS side. We recommend that you enable this feature to improve the query efficiency of memory page tables. |
| writing_throttling_trigger_percentage | The threshold for enabling write throttling. | The default value is 60. You can disable this feature in performance tests as needed. If this feature is disabled, the memory may become insufficient when a large amount of data is concurrently written. |
Memory-related parameters
share
Previous topic