a data structure in the control file that defines a consistent point of the database across all threads of a redo log
a file that contains all information necessary to recreate the metadata in the Perforce database
an approximation of the amount of time it would take the database to recover itself in the event of a system failure using its transaction logs
an automated, wireless, computerized remote temperature monitoring, recording and alert system to replace chart records, data loggers and manual temperature log reports
an automatic mechanism to guarantee that data pages changed by completed transactions are regularly written from the cache in memory to the database device
an event in which all modified database buffers are written to the datafiles by the DBWR
an event that flushes data and log buffer contents to disk, and reclaims nonarchive log file space for reuse
an event that flushes data and log buffers to disk
an event that occurs within the database whenever information is written from the caches within the SGA to disk
an I/O-intensive process that flushes all changed database pages from memory cache to disk
an operation that forces all changed, in-memory data blocks to be written out to disk
a point at which all dirty pages are written to disk and therefore represents a known consistent state of the database on disk
a point in the transaction log sequence at which all data files have been updated to reflect the information in the log
a point in time when the record described in the log is the same as the record in the queue
a process that periodically causes all dirty buffers to be written to disk
a record indicating the point in the log files where all changes have been saved to the actual database
a reference used by the recovery log to replay missing requests
a snapshot of the complete state of the system at one instant, saved to nonvolatile storage, i
a snapshot or copy of the database at a particular moment in time
a timed event to make sure that the database and shared memory contain the same data
a virtual snapshot that captures registry settings, system settings and files
The act of recording status information to the DB2 log that would be needed for recovery if DB2 abended.
In a server cluster node's registry, a snapshot of the registry cluster key or of an application key. The checkpoint is written to the quorum disk when certain events take place, such as a node failure. See also cluster database.
An identified snapshot of a database or a point at which the transactions against the database have been frozen.
Generally speaking, when data is saved to disk, it is said that a checkpoint has been reached. More specific to Cluster, it is a point in time where all committed transactions are stored on disk. With regard to the NDB storage engine, there are two types of checkpoints which work together to ensure that a consistent view of the cluster's data is maintained: Local Checkpoint (LCP): This is a checkpoint that is specific to a single node; however, LCP's take place for all nodes in the cluster more or less concurrently. An LCP involves saving all of a node's data to disk, and so usually occurs every few minutes. The precise interval varies, and depends upon the amount of data stored by the node, the level of cluster activity, and other factors. Global Checkpoint (GCP): A GCP occurs every few seconds, when transactions for all nodes are synchronized and the redo-log is flushed to disk.
The point at which all changes to the database are saved to the database file. At other times, committed changes are saved only to the transaction log.
A data structure that defines an SCN in the redo thread of a database. Checkpoints are recorded in the control file and each datafile header, and are a crucial element of recovery.
An entry in the journal file that defines a position after which run-unit updates to the database can be reversed during recovery.
A time when significant information is written on the log. Contrast with syncpoint.
checkpoint occurs when the DBWR ( database writer) process writes all modified buffers in the SGA buffer cache to the database data files. Checkpoints occur AFTER (not during) every redo log switch and also at intervals specified by initialization parameters. Set parameter LOG_CHECKPOINTS_TO_ALERT=TRUE to observe checkpoint start and end times in the database alert log. Checkpoints can be forced with the "ALTER SYSTEM CHECKPOINT;" command. Also see CKPT.