If your source is not a database - you can still set up a change replication flow which will load only the records that have changed since the last successful load.
Basically, all you need to do is to set the High watermark field and enable the change replication for the transformation:
make sure that the high watermark field is: either TIMESTAMP/DATE (or can be converted to TIMESTAMP/DATE), or NUMERIC. When configuring a specific format in Integrator to be used for data exchange, it is always possible to set the TIMESTAMP and DATE formats:
It is also possible to configure Integrator to parse all strings and automatically detect dates and timestamps. To enable automatic date parsing - check Parse Dates.