The pd_log_sdinterval operand is used to set the synchronization point dump interval. The following considerations are taken into account in order to set the synchronization point dump interval:

• Amount of system log information that is output
  A synchronization point dump is acquired each time the number of blocks of system logs specified in the pd_log_sdinterval operand is output.
  
• Elapsed time
  A synchronization point dump is acquired when a certain amount of time has elapsed (specified in the pd_log_sdinterval operand) after the last synchronization point was acquired.
  

When the synchronization point dump interval is short, the time required for database recovery during a HiRDB restart is reduced. However, online performance might be degraded because synchronization point dumps are acquired more frequently.

On the other hand, when the synchronization point dump interval is long, the time required for database recovery during a HiRDB restart is increased. However, online performance might be improved because synchronization point dumps are acquired less frequently.

The synchronization point dump interval can be determined by checking the item labeled SYNC POINT GET INTERVAL in the statistics analysis utility's system activity statistical information.

For details on tuning the synchronization point dump interval, see 23.4 Tuning the synchronization point dump interval.

This example assumes a system that has few updating transactions during the day shift (0900 to 1800 hours) and many updating transactions at night (1800 to 0900 hours):

Explanation

• During the shift in which there are few updating transactions (0900 to 1800 hours), obtain synchronization point dumps based on elapsed time.
• During the shift in which there are many updating transactions (1800 to 0900 hours), obtain synchronization point dumps based on the amount of system log information that is output.
• If additional synchronization point dumps are needed, use the pdlogsync command as necessary.