Checkpoints are used to store a transactionally-consistent state of the database quickly onto the disk.
Checkpoints affect:
▪Runtime performance
▪Recovery time performance
Checkpoints cause solidDB® to perform data I/O with high priority, which momentarily reduces the runtime performance. Typically the performance impact of checkpoints is small. Similar to merge intervals, less frequent checkpoints can mean less frequent, but longer delays before the system responds to interactive queries. More frequent checkpoints tend to minimize the worst case delays that an interactive user might experience. However, such delays may be more frequent even if they are shorter.
It is possible to control the execution of checkpoints to prevent them from occurring during, for example, periods of high user volume.
▪Set configuration parameters in the solid.ini file.
– Set the General.CheckpointInterval parameter. The default checkpoint interval is every 50000 log writes.
– Set the General.MinCheckpointTime parameter.
▪Force a checkpoint by using the ADMIN COMMAND 'makecp' command.
Frequent checkpoints can reduce the recovery time in the event of a system failure. If the checkpoint interval is small, relatively few changes to the database are made between checkpoints and consequently, few changes need to be made during recovery. To speed up recoveries, create checkpoints frequently; however, the server performance is reduced during the creation of a checkpoint. Furthermore, the speed of checkpoint creation depends on the amount of database cache used; the more database cache is used, the longer the checkpoint creation takes. The database cache size is controlled with the IndexFile.CacheSize parameter.