2.3.37 The Undofile Class

2.3.37.1 Undofile Methods

Abstract

The section discusses the Undofile class and its public methods.

Parent class.  NdbDictionary

Child classes.  None

Description.  The Undofile class models a MySQL Cluster Disk Data undofile, which stores data used for rolling back transactions.

Note

Currently, only unindexed column data can be stored on disk. Indexes and indexes columns are always stored in memory.

MySQL Cluster prior to MySQL 5.1 does not support Disk Data storage, and so does not support undo files; thus the Undofile class is unavailable for NDB API applications written against these older releases.

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

MethodPurpose / Use
Undofile()Class constructor
~Undofile()Virtual destructor
getFileNo()Gets the number of the undo file in the log file group
getLogfileGroup()Gets the name of the log file group to which the undo file belongs
getLogfileGroupId()Gets the ID of the log file group to which the undo file belongs
getNode()Gets the node where the undo file is located
getObjectId()Gets the undo file's object ID
getObjectStatus()Gets the undo file's Status
getObjectVersion()Gets the undo file's object version
getPath()Gets the undo file's file system path
getSize()Gets the size of the undo file
setLogfileGroup()Sets the undo file's log file group using the name of the log file group or a reference to the corresponding LogfileGroup object
setNode()Sets the node on which the undo file is located
setPath()Sets the file system path for the undo file
setSize()Sets the undo file's size

For detailed descriptions, signatures, and examples of use for each of these methods, see Section 2.3.37.1, “Undofile Methods”.

Types.  The undo file class defines no public types.

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

Public methods of the Undofile class.