OrientDB - Alter Cluster


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Alter Cluster command is to update attributes on an existing cluster. In this chapter you can learn how to add or modify the attributes of a cluster.

The following statement is the basic syntax of Alter Cluster command.

ALTER CLUSTER <cluster> <attribute-name> <attribute-value> 

Following are the details about the options in the above syntax.

<cluster> − Defines the cluster name.

<attribute-name> − Defines the attribute you want to change.

<attribute-value> − Defines the value you want to set for this attribute.

The following tabular format provides the list of supported attributes you can use along with Alter cluster command.

Name TypeDescription
NAME String Changes the cluster name.
STATUS String Changes the cluster status. Allowed values are ONLINE and OFFLINE. By default, clusters are online.
COMPRESSION String Defines the compression type to use. Allowed values are NOTHING, SNAPPY, GZIP, and any other compression types registered in the OCompressionFactory class.
USE_WAL Boolean Defines whether it uses the Journal when OrientDB operates against the cluster
RECORD_GROW_FACTO R 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.
RECORD_OVERFLOW_GR OW_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 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.

The following table provides the list of Conflict strategies.

Sr.No.Strategy & Description
1

Version

Throws an exception when versions are different. This is the default setting.

2

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.

3

Automerge

Merges the changes.

Example

Try the following example queries to learn Alter cluster command.

Execute the following command to change the name of a cluster from Employee to Employee2.

orientdb {db = demo}> ALTER CLUSTER Employee NAME Employee2

If the above command is executed successfully, you will get the following output.

Cluster updated successfully 

Execute the following command to change the name of a cluster from Employee2 to Employee using cluster ID.

orientdb {db = demo}> ALTER CLUSTER 12 NAME Employee 

If the above command is executed successfully, you will get the following output.

Cluster updated successfully

Execute the following command to change the cluster conflict strategy to automerge.

orientdb {db = demo}> ALTER CLUSTER V CONFICTSTRATEGY automerge 

If the above command is executed successfully, you will get the following output.

Cluster updated successfully 


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