DataSync settings are accessed from the Gear menu
The Sync Behavior page controls how DataSync behaves during the synchronization process
Select Default Target
This drop down box contains the list of all the databases defined
in the CDD. The selected database will be used as the target
for Table Syncs and the default target for Transformation Syncs. The
target database for transformations can be overridden when defining
transformations.
Full Reload Threshold(%)
The percentage amount that appears in Full Reload Threshold
is the number that will determine if it is more efficient to perform
a full reload or an incremental update based on the percentage of
rows changed in the source table. This number should be very small,
in the range of 3 to 20 percent.
Max Worker Threads
Enter a number in the Max Worker Threads text box. (Recommended
= 4 threads per CPU on the Data Sync machine) The maximum number is
the number of threads on the PC (and also the number of servers on
the host database server) that can be used when processing the synchronization.
For example, if there are 1000 tables of the same size, 1 out of 3
threads would process about 333 tables each. Increasing the number
of threads uses more resources on the PC and on the host database
server, but can also increase performance.
Take note that increasing the thread count to a level that is too high
can severely impact performance and possibly cause failures. It is
strongly recommended that you do not exceed ten threads per CPU available
on the Data Synchronization machine and also to consider the system's
total memory, since each thread can allocate large blocks of memory
when processing large tables.
In order to test the effects of multiple threads, create a group and
then synchronize the group.
Tip: A few tests with different
threading values can determine a good level for Max Worker Threads
for your system through examination of the group synchronization time.
Full Synchronization
Behavior
There are two methods to process a full synchronization. One
is to drop and recreate the target table every time. The other is
to delete the data in the target table. When deleting data, we can
either truncate the data or delete the data. Truncation
is typically much faster, but not all systems support truncate. If
you select truncation, and the target does not support truncation,
you will receive a warning and Delete
will be used instead. An advantage to dropping and recreating the
table is that changes in the source table will automatically be reflected
in the target and so the system is self-healing. However, there
may be customizations on the
target server. In this case, we want to purge the data instead. Truncation, while faster, is not
typically logged and therefore the user will have to redo a failed
sync. Deletion works on every
system, but is much slower than dropping and adding the schema or
truncation.
If the target database does not support truncation, a warning appears
for every table selected for deletion even though the synchronization
continues and succeeds.
There are two options for Full Synchronization
Behavior:
Method Used to Purge Data:
There are two options for Purge target table and preserve schema: