Documentation Home
MySQL Cluster API Developer Guide
Download this Manual
PDF (US Ltr) - 5.0Mb
PDF (A4) - 4.9Mb
EPUB - 1.9Mb
HTML Download (TGZ) - 1.9Mb
HTML Download (Zip) - 1.9Mb

2.3.13 The LogfileGroup Class


This section discusses the LogfileGroup class, which represents a MySQL Cluster Disk Data logfile group.

Parent class.  NdbDictionary

Child classes.  None

Description.  This class represents a MySQL Cluster Disk Data logfile group, which is used for storing Disk Data undofiles. For general information about logfile groups and undofiles, see MySQL Cluster Disk Data Tables, in the MySQL Manual.


Currently, only unindexed column data can be stored on disk. Indexes and indexes columns continue to be stored in memory as with previous versions of MySQL Cluster.

MySQL Cluster prior to MySQL 5.1 does not support Disk Data storage, and so does not support logfile groups; thus the LogfileGroup class is unavailable for NDB API applications written against such releases.

Methods.  The following table lists the public methods of this class and the purpose or use of each method:

Method Purpose / Use
LogfileGroup() Class constructor
~LogfileGroup() Virtual destructor
getAutoGrowSpecification() Gets the logfile group's AutoGrowSpecification values
getName() Retrieves the logfile group's name
getObjectId() Get the object ID of the logfile group
getObjectStatus() Gets the logfile group's object status value
getObjectVersion() Retrieves the logfile group's object version
getUndoBufferSize() Gets the size of the logfile group's UNDO buffer
getUndoFreeWords() Retrieves the amount of free space in the UNDO buffer
setAutoGrowSpecification() Sets AutoGrowSpecification values for the logfile group
setName() Sets the name of the logfile group
setUndoBufferSize() Sets the size of the logfile group's UNDO buffer.

For detailed descriptions, signatures, and examples of use for each of these methods, see Section, “LogfileGroup Methods”.

Types.  The LogfileGroup class does not itself define any public types. However, two of its methods make use of the AutoGrowSpecification data structure as a parameter or return value. For more information, see Section 2.3.1, “The AutoGrowSpecification Structure”.

Class diagram.  This diagram shows all the available public methods of the LogfileGroup class:

Figure 2.10 NdbDictionary::Object::LogfileGroup

Public methods of the LogfileGroup class.

User Comments
Sign Up Login You must be logged in to post a comment.