Related Configuration Parameters

full_rewrite_on_combine

Specifies whether all blocks are to be rewritten by the COMBINE command. Setting this option to true can be used to avoid or undo block fragmentation introduced by partial update propagation.

Default: false

full_rewrite_on_update_propagation

Specifies whether all blocks are to be rewritten by the system-triggered propagation process. Setting this option to true can be used to avoid block fragmentation introduced by partial update propagation.

Default: false

max_number_propagate_retries

Specifies the maximum number of retries for failed automatic update propagation. When propagation for a certain table fails, Vector will retry propagating this table if no alternative tables are possible.

Default: 3

max_table_update_ratio

Specifies a per-table maximum percentage of in-memory updates (that is, the number of updates divided by the number of stable tuples). When this limit is reached, the system propagates to disk in memory updates for this table.

• Limits: 0.01 to 1.0

• Default: 0.05

memory.update_maximum

The maximum amount of memory, in bytes, that can be used by memory-buffered updates. If memory.update_allocated reaches this limit, propagation (automatic COMBINE) is triggered. If propagation is not successful, and the limit is reached, the memory-buffered updates may stop being accepted.

memory.update_allocated

The total memory, in bytes, used by memory-buffered updates of the committed transactions. The amount of this memory can be reduced by the automatic propagation mechanism. It can also be freed manually by issuing the command CALL VECTORWISE(COMBINE); COMMIT;, which will propagate the inmemory updates to disk.