By default, the Integration Service does not preserve row order when multiple partitions read from a single file source. To preserve row order when multiple partitions read from a single file source, configure concurrent read partitioning. You can configure the following options:
Optimize throughput.
The Integration Service does not preserve row order when multiple partitions read from a single file source. Use this option if the order in which multiple partitions read from a file source is not important.
Keep relative input row order.
Preserves the sort order of the input rows read by each partition. Use this option if you want to preserve the sort order of the input rows read by each partition.
The following table shows an example sort order of a file source with 10 rows by two partitions:
Partition
Rows Read
Partition #1
1,3,5,8,9
Partition #2
2,4,6,7,10
Keep absolute input row order.
Preserves the sort order of all input rows read by all partitions. Use this option if you want to preserve the sort order of the input rows each time the session runs. In a pass-through mapping with passive transformations, the order of the rows written to the target will be in the same order as the input rows.
The following table shows an example sort order of a file source with 10 rows by two partitions:
Partition
Rows Read
Partition #1
1,2,3,4,5
Partition #2
6,7,8,9,10
By default, the Integration Service uses the Keep absolute input row order option in sessions configured with the resume from the last checkpoint recovery strategy.