Vertica Analytics Platform Version 9.2.x Documentation

Tuple Mover Parameters

These parameters control how the Tuple Mover operates.

Parameters Description

ActivePartitionCount

Sets the number of active partitions. The active partitions are those most recently created. For example:

=> ALTER DATABASE mydb SET ActivePartitionCount = 2;	

For information about how the Tuple Mover treats active and inactive partitions during a mergeout operation, see Partition Mergeout.

Default Value: 1

CancelTMTimeout

When partition, copy table, and rebalance operations encounter a conflict with an internal Tuple Mover job, those operations attempt to cancel the conflicting Tuple Mover job. This parameter specifies the amount of time, in seconds, that the blocked operation waits for the Tuple Mover cancellation to take effect. If the operation is unable to cancel the Tuple Mover job within limit specified by this parameter, the operation displays an error and rolls back.

Default Value: 300

EnableTMOnRecoveringNode

When enabled, allows Tuple Mover to perform moveout and mergeout activities on nodes with a node state of RECOVERING. Enabling Tuple Mover reduces the number of ROS containers generated during recovery. Having fewer than 1024 ROS containers per projection allows Vertica to maintain optimal recovery performance.

Default Value: 1

MaxMrgOutROSSizeMB

Specifies in MB the maximum size of ROS containers that are candidates for mergeout operations. The Tuple Mover avoids merging ROS containers that are larger than this setting.

Default Value: -1 (no maximum limit)

MergeOutInterval

Specifies in seconds how frequently the Tuple Mover checks the mergeout request queue for pending requests:
  1. If the queue contains mergeout requests, the Tuple Mover does nothing and goes back to sleep.
  2. If the queue is empty, the Tuple Mover:
    • Processes pending storage location move requests.
    • Checks for new unqueued purge requests and adds them to the queue.

    It then goes back to sleep.

Default Value: 600

MoveOutInterval

Specifies in seconds how frequently Tuple Mover checks for new data in the WOS to move to ROS.

Default Value: 300

MoveOutMaxAgeTime

Specifies in seconds how long the Tuple Mover waits before it is forced to write the WOS to disk.

Default Value: 1800

MoveOutSizePct

The percentage of the WOS that can be filled with data before the Tuple Mover performs a moveout operation.

Default Value: 0

PurgeMergeoutPercent

Specifies as a percentage the threshold of deleted records in a ROS container that invokes an automatic mergeout operation, to purge those records. Vertica only counts the number of 'aged-out' delete vectors—that is, delete vectors that are as 'old' or older than the ancient history mark (AHM) epoch.

This threshold applies to all ROS containers for non-partitioned tables. It also applies to ROS containers of all inactive partitions. In both cases, aged-out delete vectors are permanently purged from the ROS container.

This configuration parameter only applies to automatic mergeout operations. It does not apply to manual mergeout operations that are invoked by calling meta-functions DO_TM_TASK('mergeout') and PURGE.

Default Value: 20 (percent)