SQL - ALTER CLUSTER

Updates attributes on an existing cluster.

Syntax

  1. ALTER CLUSTER <cluster> <attribute-name> <attribute-value>
  • <cluster> Defines the cluster you want to change. You can use its logical name or ID. Beginning with version 2.2, you can use the wildcard * to update multiple clusters together.
  • <attribute-name> Defines the attribute you want to change. For a list of supported attributes, see the table below.
  • <attribute-value> Defines the value you want to set.

Examples

  • Change the name of a cluster, using its name:

    1. orientdb> ALTER CLUSTER profile NAME profile2

  • Change the name of a cluster, using its ID:

    1. orientdb> ALTER CLUSTER 9 NAME profile2

  • Update the cluster conflict strategy to automerge:

    1. orientdb> ALTER CLUSTER V CONFLICTSTRATEGY automerge

  • Put cluster V_2012 offline:

    1. orientdb> ALTER CLUSTER V_2012 STATUS OFFLINE

  • Update multiple clusters with a similar name:

    1. orientdb> ALTER CLUSTER employee* status offline

For more information see, CREATE CLUSTER, DROP CLUSTER, ALTER CLUSTER commands. For more information on other commands, see Console and SQL commands.

Supported Attributes

Name Type Support Description
NAME String Changes the cluster name.
STATUS String Changes the cluster status. Allowed values are ONLINE and OFFLINE. By default, clusters are online. When offline, OrientDB no longer opens the physical files for the cluster. You may find this useful when you want to archive old data elsewhere and restore when needed.
COMPRESSION String Defines the compression type to use. Allowed values are NOTHING, SNAPPY, GZIP, and any other compression types registered in the OCompressionFactory class. OrientDB class the compress() method each time it saves the record to the storage, and the uncompress() method each time it loads the record from storage. You can also use the OCompression interface to manage encryption.
USE_WAL Boolean Defines whether it uses the Journal (Write Ahead Log) when OrientDB operates against the cluster.
RECORD_GROW_FACTOR Integer Defines the grow factor to save more space on record creation. You may find this useful when you update the record with additional information. In larger records, this avoids defragmentation, as OrientDB doesn’t have to find new space in the event of updates with more data.
RECORD_OVERFLOW_GROW_FACTOR Integer Defines grow factor on updates. When it reaches the size limit, is uses this setting to get more space, (factor > 1).
CONFLICTSTRATEGY String 2.0+ Defines the strategy it uses to handle conflicts in the event that OrientDB MVCC finds an update or a delete operation it executes against an old record. If you don’t define a strategy at the cluster-level, it uses the database-level configuration. For more information on supported strategies, see the section below.

Supported Conflict Strategies

Strategy Description
version Throws an exception when versions are different. This is the default setting.
content In the event that the versions are different, it checks for changes in the content, otherwise it uses the highest version to avoid throwing an exception.
automerge Merges the changes.

To know more about other SQL commands, take a look at SQL commands.