Transaction Group Size
Checkpoint client every n [(allow min to max)] transactions
Checkpoint client every n [(allow min to max)] update records
Checkpoint options can be combined with "or." For example:
Checkpoint client every n [(allow min to max)] audit blocks or every n [(allow min to max)] transactions
Checkpoint client every n [(allow min to max)] audit blocks or every n [(allow min to max)] update records
Checkpoint client every 100 (allow any) audit blocks
%Checkpoint client every 1000 (allow 1 - 9999999) records
%Checkpoint client every 200 (allow any) transactions
%Checkpoint client every 10 (allow 1 - 36000) seconds
This Checkpoint option specifies the size of a transaction group. DBEngine ends a transaction group at the first quiet point (natural or super) after reaching the Checkpoint value. This ensures that transaction groups are roughly the same size and reduces the overhead associated with ending transaction groups due to frequent QPTs.
Updated records in a transaction group are not available to accessories until the end of the transaction group is reached and the whole group is committed to the client database. Therefore, smaller transaction groups make the individual updates available sooner.
The disadvantage of smaller transaction groups is that DBEngine must send state information records at the end of each group to reflect the new location in the audit trail. The accessory must update its control tables with this state information, which is additional overhead. The target database might have some constraints on how many records can be updated in one group. If so, the Checkpoint option would need to be low enough to stay within those constraints.