The following table compares the original operation mode delta_datashipping with the operation mode logreplay available as of SAP HANA >= SPS 11:
|Operation mode||SAP HANA Version||Description||Advantages|
|delta_datashipping||no restriction||Synchronization between primary and secondary site is implemented via regular delta data shippings from primary to secondary site.|| |
|logreplay||>= 1.00.110||Synchronization between primary and secondary site is implemented purely based on redo logs|| |
|logreplay_readaccess||>= 2.00|| |
Synchronization between primary and secondary site is implemented purely based on redo logs
Secondary site can be used for read-only accesses (on column store tables)
The operation mode can be defined with the following parameter:
global.ini -> [system_replication] -> operation_mode
In 3-tier environments the following details can be considered for the logreplay mode:
- If the tertiary system is down, the logs are only saved on the secondary system, not on the primary system.
- If the secondary system is down and you want to use the tertiary system as secondary system, usually a full sync is required, because the logs retained on primary site are meant for the secondary site and so they may not be compatible with the tertiary system.