This topic introduces the minor compaction parameters and describes how to set these parameters.
Minor compaction parameters
| Parameter | Description | Default value | Value range |
|---|---|---|---|
| minor_compact_trigger | The number of SSTables for triggering a minor compaction. It is a tenant-level parameter. | 2 | [0, 16] |
| freeze_trigger_percentage | The maximum percentage of memory space used by the MemStore of the tenant to trigger a minor freeze. This is a tenant-level parameter. | 20 | (0, 100) |
| memstore_limit_percentage | The percentage of MemStore memory to the total memory of the tenant. It is a cluster-level parameter.
NoteStarting from OceanBase Database V4.3.0, the V4.3.x series provide the tenant-level hidden parameter
|
0 | [0, 100) |
Modify minor compaction parameters by using SQL statements
Log in to the database as a tenant administrator.
Execute the following sample statements to modify minor compaction parameters:
obclient> ALTER SYSTEM SET minor_compact_trigger=2; obclient> ALTER SYSTEM SET major_compact_trigger=10; obclient> ALTER SYSTEM SET freeze_trigger_percentage=20; obclient> ALTER SYSTEM SET memstore_limit_percentage=50;After the parameters are modified, you can execute the
SHOW PARAMETERSstatement to check whether the modification is successful.Here are some examples:
obclient> SHOW PARAMETERS LIKE 'minor_compact_trigger'; obclient> SHOW PARAMETERS LIKE 'major_compact_trigger'; obclient> SHOW PARAMETERS LIKE 'freeze_trigger_percentage'; obclient> SHOW PARAMETERS LIKE 'memstore_limit_percentage';
